diff --git a/source/libs/executor/src/tfill.c b/source/libs/executor/src/tfill.c
index 55ef019d767da89c18a7caf8db31737c68bf99af..4e0dff9d4f3474c2b2335d79b0cde362f566dfa1 100644
--- a/source/libs/executor/src/tfill.c
+++ b/source/libs/executor/src/tfill.c
@@ -66,20 +66,25 @@ static void setNullRow(SSDataBlock* pBlock, SFillInfo* pFillInfo, int32_t rowInd
 }
 
 static void doSetUserSpecifiedValue(SColumnInfoData* pDst, SVariant* pVar, int32_t rowIndex, int64_t currentKey) {
+  bool isNull = (TSDB_DATA_TYPE_NULL == pVar->nType) ? true : false;
   if (pDst->info.type == TSDB_DATA_TYPE_FLOAT) {
     float v = 0;
-    GET_TYPED_DATA(v, float, pVar->nType, &pVar->i);
-    colDataSetVal(pDst, rowIndex, (char*)&v, false);
+    GET_TYPED_DATA(v, float, pVar->nType, &pVar->f);
+    colDataSetVal(pDst, rowIndex, (char*)&v, isNull);
   } else if (pDst->info.type == TSDB_DATA_TYPE_DOUBLE) {
     double v = 0;
-    GET_TYPED_DATA(v, double, pVar->nType, &pVar->i);
-    colDataSetVal(pDst, rowIndex, (char*)&v, false);
+    GET_TYPED_DATA(v, double, pVar->nType, &pVar->d);
+    colDataSetVal(pDst, rowIndex, (char*)&v, isNull);
   } else if (IS_SIGNED_NUMERIC_TYPE(pDst->info.type)) {
     int64_t v = 0;
     GET_TYPED_DATA(v, int64_t, pVar->nType, &pVar->i);
-    colDataSetVal(pDst, rowIndex, (char*)&v, false);
+    colDataSetVal(pDst, rowIndex, (char*)&v, isNull);
+  } else if (IS_UNSIGNED_NUMERIC_TYPE(pDst->info.type)) {
+    uint64_t v = 0;
+    GET_TYPED_DATA(v, uint64_t, pVar->nType, &pVar->u);
+    colDataSetVal(pDst, rowIndex, (char*)&v, isNull);
   } else if (pDst->info.type == TSDB_DATA_TYPE_TIMESTAMP) {
-    colDataSetVal(pDst, rowIndex, (const char*)&currentKey, false);
+    colDataSetVal(pDst, rowIndex, (const char*)&currentKey, isNull);
   } else {  // varchar/nchar data
     colDataSetNULL(pDst, rowIndex);
   }
diff --git a/source/libs/executor/src/timesliceoperator.c b/source/libs/executor/src/timesliceoperator.c
index cb74392a10953331d76a8d6af46f91296812ea13..b01998564513d20d17267a64776d0d20f2461c96 100644
--- a/source/libs/executor/src/timesliceoperator.c
+++ b/source/libs/executor/src/timesliceoperator.c
@@ -312,6 +312,7 @@ static bool genInterpolationResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp
       case TSDB_FILL_SET_VALUE_F: {
         SVariant* pVar = &pSliceInfo->pFillColInfo[fillColIndex].fillVal;
 
+        bool isNull = (TSDB_DATA_TYPE_NULL == pVar->nType) ? true : false;
         if (pDst->info.type == TSDB_DATA_TYPE_FLOAT) {
           float v = 0;
           if (!IS_VAR_DATA_TYPE(pVar->nType)) {
@@ -319,7 +320,7 @@ static bool genInterpolationResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp
           } else {
             v = taosStr2Float(varDataVal(pVar->pz), NULL);
           }
-          colDataSetVal(pDst, rows, (char*)&v, false);
+          colDataSetVal(pDst, rows, (char*)&v, isNull);
         } else if (pDst->info.type == TSDB_DATA_TYPE_DOUBLE) {
           double v = 0;
           if (!IS_VAR_DATA_TYPE(pVar->nType)) {
@@ -327,7 +328,7 @@ static bool genInterpolationResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp
           } else {
             v = taosStr2Double(varDataVal(pVar->pz), NULL);
           }
-          colDataSetVal(pDst, rows, (char*)&v, false);
+          colDataSetVal(pDst, rows, (char*)&v, isNull);
         } else if (IS_SIGNED_NUMERIC_TYPE(pDst->info.type)) {
           int64_t v = 0;
           if (!IS_VAR_DATA_TYPE(pVar->nType)) {
@@ -335,7 +336,7 @@ static bool genInterpolationResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp
           } else {
             v = taosStr2Int64(varDataVal(pVar->pz), NULL, 10);
           }
-          colDataSetVal(pDst, rows, (char*)&v, false);
+          colDataSetVal(pDst, rows, (char*)&v, isNull);
         } else if (IS_UNSIGNED_NUMERIC_TYPE(pDst->info.type)) {
           uint64_t v = 0;
           if (!IS_VAR_DATA_TYPE(pVar->nType)) {
@@ -343,7 +344,7 @@ static bool genInterpolationResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp
           } else {
             v = taosStr2UInt64(varDataVal(pVar->pz), NULL, 10);
           }
-          colDataSetVal(pDst, rows, (char*)&v, false);
+          colDataSetVal(pDst, rows, (char*)&v, isNull);
         } else if (IS_BOOLEAN_TYPE(pDst->info.type)) {
           bool v = false;
           if (!IS_VAR_DATA_TYPE(pVar->nType)) {
@@ -351,7 +352,7 @@ static bool genInterpolationResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp
           } else {
             v = taosStr2Int8(varDataVal(pVar->pz), NULL, 10);
           }
-          colDataSetVal(pDst, rows, (char*)&v, false);
+          colDataSetVal(pDst, rows, (char*)&v, isNull);
         }
 
         ++fillColIndex;
diff --git a/tests/script/tsim/parser/fill.sim b/tests/script/tsim/parser/fill.sim
index a66e7d6ab72e0c85a85035565c2e8fd9da70b0af..0534aa5d5b762c24bb50bba9c52b6733a2d7b429 100644
--- a/tests/script/tsim/parser/fill.sim
+++ b/tests/script/tsim/parser/fill.sim
@@ -1224,4 +1224,104 @@ if $data42 != NULL then
   return -1
 endi
 
+print ===================== TD-3625 test fill value NULL
+sql use $db
+
+sql select _wstart,_wend,count(*) from tm0 where ts >= '2020-01-01 01:03:06.000' and ts <= '2020-01-01 01:03:10.000' interval(1s) fill(value, NULL);
+
+if $rows != 5 then
+  return -1
+endi
+
+if $data02 != NULL then
+  return -1
+endi
+
+if $data12 != 1 then
+  return -1
+endi
+
+if $data22 != 1 then
+  return -1
+endi
+
+if $data32 != 1 then
+  return -1
+endi
+
+if $data42 != NULL then
+  return -1
+endi
+
+sql select _wstart,_wend,count(*),sum(k),avg(k) from tm0 where ts >= '2020-01-01 01:03:06.000' and ts <= '2020-01-01 01:03:10.000' interval(1s) fill(value, 1, NULL, 1);
+
+if $rows != 5 then
+  return -1
+endi
+
+if $data02 != 1 then
+  return -1
+endi
+
+if $data12 != 1 then
+  return -1
+endi
+
+if $data22 != 1 then
+  return -1
+endi
+
+if $data32 != 1 then
+  return -1
+endi
+
+if $data42 != 1 then
+  return -1
+endi
+
+
+if $data03 != NULL then
+  return -1
+endi
+
+if $data13 != 7 then
+  return -1
+endi
+
+if $data23 != 8 then
+  return -1
+endi
+
+if $data33 != 9 then
+  return -1
+endi
+
+if $data43 != NULL then
+  return -1
+endi
+
+
+if $data04 != 1.000000000 then
+  return -1
+endi
+
+if $data14 != 7.000000000 then
+  return -1
+endi
+
+if $data24 != 8.000000000 then
+  return -1
+endi
+
+if $data34 != 9.000000000 then
+  return -1
+endi
+
+if $data44 != 1.000000000 then
+  return -1
+endi
+
+
 system sh/exec.sh -n dnode1 -s stop -x SIGINT
+
+
diff --git a/tests/system-test/2-query/interp.py b/tests/system-test/2-query/interp.py
index b6cefbe36fda9954188d59f813db9be4069a1af8..986c63839b1c6e9cfc8c8c6b857a668146d03237 100644
--- a/tests/system-test/2-query/interp.py
+++ b/tests/system-test/2-query/interp.py
@@ -147,6 +147,57 @@ class TDTestCase:
             tdSql.checkData(11, 0, 15)
             tdSql.checkData(12, 0, 1)
 
+        for col in col_list:
+            tdSql.query(f"select interp({col}) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, 1.0)")
+            tdSql.checkRows(13)
+            tdSql.checkData(0, 0, 1)
+            tdSql.checkData(1, 0, 5)
+            tdSql.checkData(2, 0, 1)
+            tdSql.checkData(3, 0, 1)
+            tdSql.checkData(4, 0, 1)
+            tdSql.checkData(5, 0, 1)
+            tdSql.checkData(6, 0, 10)
+            tdSql.checkData(7, 0, 1)
+            tdSql.checkData(8, 0, 1)
+            tdSql.checkData(9, 0, 1)
+            tdSql.checkData(10, 0, 1)
+            tdSql.checkData(11, 0, 15)
+            tdSql.checkData(12, 0, 1)
+
+        for col in col_list:
+            tdSql.query(f"select interp({col}) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, true)")
+            tdSql.checkRows(13)
+            tdSql.checkData(0, 0, 1)
+            tdSql.checkData(1, 0, 5)
+            tdSql.checkData(2, 0, 1)
+            tdSql.checkData(3, 0, 1)
+            tdSql.checkData(4, 0, 1)
+            tdSql.checkData(5, 0, 1)
+            tdSql.checkData(6, 0, 10)
+            tdSql.checkData(7, 0, 1)
+            tdSql.checkData(8, 0, 1)
+            tdSql.checkData(9, 0, 1)
+            tdSql.checkData(10, 0, 1)
+            tdSql.checkData(11, 0, 15)
+            tdSql.checkData(12, 0, 1)
+
+        for col in col_list:
+            tdSql.query(f"select interp({col}) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, NULL)")
+            tdSql.checkRows(13)
+            tdSql.checkData(0, 0, None)
+            tdSql.checkData(1, 0, 5)
+            tdSql.checkData(2, 0, None)
+            tdSql.checkData(3, 0, None)
+            tdSql.checkData(4, 0, None)
+            tdSql.checkData(5, 0, None)
+            tdSql.checkData(6, 0, 10)
+            tdSql.checkData(7, 0, None)
+            tdSql.checkData(8, 0, None)
+            tdSql.checkData(9, 0, None)
+            tdSql.checkData(10, 0, None)
+            tdSql.checkData(11, 0, 15)
+            tdSql.checkData(12, 0, None)
+
         tdSql.query(f"select interp(c4) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, 1)")
         tdSql.checkRows(13)
         tdSql.checkData(0, 0, 1.0)
@@ -163,6 +214,54 @@ class TDTestCase:
         tdSql.checkData(11, 0, 15.0)
         tdSql.checkData(12, 0, 1.0)
 
+        tdSql.query(f"select interp(c4) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, 1.0)")
+        tdSql.checkRows(13)
+        tdSql.checkData(0, 0, 1.0)
+        tdSql.checkData(1, 0, 5.0)
+        tdSql.checkData(2, 0, 1.0)
+        tdSql.checkData(3, 0, 1.0)
+        tdSql.checkData(4, 0, 1.0)
+        tdSql.checkData(5, 0, 1.0)
+        tdSql.checkData(6, 0, 10.0)
+        tdSql.checkData(7, 0, 1.0)
+        tdSql.checkData(8, 0, 1.0)
+        tdSql.checkData(9, 0, 1.0)
+        tdSql.checkData(10, 0, 1.0)
+        tdSql.checkData(11, 0, 15.0)
+        tdSql.checkData(12, 0, 1.0)
+
+        tdSql.query(f"select interp(c4) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, true)")
+        tdSql.checkRows(13)
+        tdSql.checkData(0, 0, 1.0)
+        tdSql.checkData(1, 0, 5.0)
+        tdSql.checkData(2, 0, 1.0)
+        tdSql.checkData(3, 0, 1.0)
+        tdSql.checkData(4, 0, 1.0)
+        tdSql.checkData(5, 0, 1.0)
+        tdSql.checkData(6, 0, 10.0)
+        tdSql.checkData(7, 0, 1.0)
+        tdSql.checkData(8, 0, 1.0)
+        tdSql.checkData(9, 0, 1.0)
+        tdSql.checkData(10, 0, 1.0)
+        tdSql.checkData(11, 0, 15.0)
+        tdSql.checkData(12, 0, 1.0)
+
+        tdSql.query(f"select interp(c4) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, NULL)")
+        tdSql.checkRows(13)
+        tdSql.checkData(0, 0, None)
+        tdSql.checkData(1, 0, 5.0)
+        tdSql.checkData(2, 0, None)
+        tdSql.checkData(3, 0, None)
+        tdSql.checkData(4, 0, None)
+        tdSql.checkData(5, 0, None)
+        tdSql.checkData(6, 0, 10.0)
+        tdSql.checkData(7, 0, None)
+        tdSql.checkData(8, 0, None)
+        tdSql.checkData(9, 0, None)
+        tdSql.checkData(10, 0, None)
+        tdSql.checkData(11, 0, 15.0)
+        tdSql.checkData(12, 0, None)
+
         tdSql.query(f"select interp(c5) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, 1)")
         tdSql.checkRows(13)
         tdSql.checkData(0, 0, 1.0)
@@ -179,6 +278,54 @@ class TDTestCase:
         tdSql.checkData(11, 0, 15.0)
         tdSql.checkData(12, 0, 1.0)
 
+        tdSql.query(f"select interp(c5) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, 1.0)")
+        tdSql.checkRows(13)
+        tdSql.checkData(0, 0, 1.0)
+        tdSql.checkData(1, 0, 5.0)
+        tdSql.checkData(2, 0, 1.0)
+        tdSql.checkData(3, 0, 1.0)
+        tdSql.checkData(4, 0, 1.0)
+        tdSql.checkData(5, 0, 1.0)
+        tdSql.checkData(6, 0, 10.0)
+        tdSql.checkData(7, 0, 1.0)
+        tdSql.checkData(8, 0, 1.0)
+        tdSql.checkData(9, 0, 1.0)
+        tdSql.checkData(10, 0, 1.0)
+        tdSql.checkData(11, 0, 15.0)
+        tdSql.checkData(12, 0, 1.0)
+
+        tdSql.query(f"select interp(c5) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, true)")
+        tdSql.checkRows(13)
+        tdSql.checkData(0, 0, 1.0)
+        tdSql.checkData(1, 0, 5.0)
+        tdSql.checkData(2, 0, 1.0)
+        tdSql.checkData(3, 0, 1.0)
+        tdSql.checkData(4, 0, 1.0)
+        tdSql.checkData(5, 0, 1.0)
+        tdSql.checkData(6, 0, 10.0)
+        tdSql.checkData(7, 0, 1.0)
+        tdSql.checkData(8, 0, 1.0)
+        tdSql.checkData(9, 0, 1.0)
+        tdSql.checkData(10, 0, 1.0)
+        tdSql.checkData(11, 0, 15.0)
+        tdSql.checkData(12, 0, 1.0)
+
+        tdSql.query(f"select interp(c5) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, NULL)")
+        tdSql.checkRows(13)
+        tdSql.checkData(0, 0, None)
+        tdSql.checkData(1, 0, 5.0)
+        tdSql.checkData(2, 0, None)
+        tdSql.checkData(3, 0, None)
+        tdSql.checkData(4, 0, None)
+        tdSql.checkData(5, 0, None)
+        tdSql.checkData(6, 0, 10.0)
+        tdSql.checkData(7, 0, None)
+        tdSql.checkData(8, 0, None)
+        tdSql.checkData(9, 0, None)
+        tdSql.checkData(10, 0, None)
+        tdSql.checkData(11, 0, 15.0)
+        tdSql.checkData(12, 0, None)
+
         tdSql.query(f"select interp(c6) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, 1)")
         tdSql.checkRows(13)
         tdSql.checkData(0, 0, True)
@@ -195,6 +342,54 @@ class TDTestCase:
         tdSql.checkData(11, 0, True)
         tdSql.checkData(12, 0, True)
 
+        tdSql.query(f"select interp(c6) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, 1.0)")
+        tdSql.checkRows(13)
+        tdSql.checkData(0, 0, True)
+        tdSql.checkData(1, 0, True)
+        tdSql.checkData(2, 0, True)
+        tdSql.checkData(3, 0, True)
+        tdSql.checkData(4, 0, True)
+        tdSql.checkData(5, 0, True)
+        tdSql.checkData(6, 0, True)
+        tdSql.checkData(7, 0, True)
+        tdSql.checkData(8, 0, True)
+        tdSql.checkData(9, 0, True)
+        tdSql.checkData(10, 0, True)
+        tdSql.checkData(11, 0, True)
+        tdSql.checkData(12, 0, True)
+
+        tdSql.query(f"select interp(c6) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, true)")
+        tdSql.checkRows(13)
+        tdSql.checkData(0, 0, True)
+        tdSql.checkData(1, 0, True)
+        tdSql.checkData(2, 0, True)
+        tdSql.checkData(3, 0, True)
+        tdSql.checkData(4, 0, True)
+        tdSql.checkData(5, 0, True)
+        tdSql.checkData(6, 0, True)
+        tdSql.checkData(7, 0, True)
+        tdSql.checkData(8, 0, True)
+        tdSql.checkData(9, 0, True)
+        tdSql.checkData(10, 0, True)
+        tdSql.checkData(11, 0, True)
+        tdSql.checkData(12, 0, True)
+
+        tdSql.query(f"select interp(c6) from {dbname}.{tbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(value, NULL)")
+        tdSql.checkRows(13)
+        tdSql.checkData(0, 0, None)
+        tdSql.checkData(1, 0, True)
+        tdSql.checkData(2, 0, None)
+        tdSql.checkData(3, 0, None)
+        tdSql.checkData(4, 0, None)
+        tdSql.checkData(5, 0, None)
+        tdSql.checkData(6, 0, True)
+        tdSql.checkData(7, 0, None)
+        tdSql.checkData(8, 0, None)
+        tdSql.checkData(9, 0, None)
+        tdSql.checkData(10, 0, None)
+        tdSql.checkData(11, 0, True)
+        tdSql.checkData(12, 0, None)
+
         ## {} ...
         tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:01', '2020-02-01 00:00:04') every(1s) fill(value, 1)")
         tdSql.checkRows(4)
@@ -2587,25 +2782,25 @@ class TDTestCase:
 
         tdSql.checkData(0, 0, '2020-02-02 00:00:00.000')
 
-        tdSql.checkData(0, 2, False)
+        tdSql.checkData(0, 2, None)
         tdSql.checkData(1, 2, False)
-        tdSql.checkData(2, 2, False)
+        tdSql.checkData(2, 2, None)
         tdSql.checkData(3, 2, True)
-        tdSql.checkData(4, 2, False)
+        tdSql.checkData(4, 2, None)
         tdSql.checkData(5, 2, False)
-        tdSql.checkData(6, 2, False)
+        tdSql.checkData(6, 2, None)
         tdSql.checkData(7, 2, True)
-        tdSql.checkData(8, 2, False)
+        tdSql.checkData(8, 2, None)
         tdSql.checkData(9, 2, True)
-        tdSql.checkData(10, 2, False)
+        tdSql.checkData(10, 2, None)
         tdSql.checkData(11, 2, False)
-        tdSql.checkData(12, 2, False)
+        tdSql.checkData(12, 2, None)
         tdSql.checkData(13, 2, False)
-        tdSql.checkData(14, 2, False)
+        tdSql.checkData(14, 2, None)
         tdSql.checkData(15, 2, None)
-        tdSql.checkData(16, 2, False)
+        tdSql.checkData(16, 2, None)
         tdSql.checkData(17, 2, None)
-        tdSql.checkData(18, 2, False)
+        tdSql.checkData(18, 2, None)
 
         tdSql.checkData(18, 0, '2020-02-02 00:00:18.000')