diff --git a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBError.java b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBError.java
index eeaa1d4df544d7e91bdaa7093badf3bd5f4beb07..c7717e331b39247542d1a022cafd1cab2ac65627 100644
--- a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBError.java
+++ b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBError.java
@@ -31,8 +31,8 @@ public class TSDBError {
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_UNSUPPORTED_ENCODING, "Unsupported encoding");
 
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_JNI_TDENGINE_ERROR, "internal error of database");
-        TSDBErrorMap.put(TSDBErrorNumbers.ERROR_JNI_CONNECTION_NULL, "JNI connection already closed");
-        TSDBErrorMap.put(TSDBErrorNumbers.ERROR_JNI_RESULT_SET_NULL, "invalid JNI result set");
+        TSDBErrorMap.put(TSDBErrorNumbers.ERROR_JNI_CONNECTION_NULL, "JNI connection is NULL");
+        TSDBErrorMap.put(TSDBErrorNumbers.ERROR_JNI_RESULT_SET_NULL, "JNI result set is NULL");
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_JNI_NUM_OF_FIELDS_0, "invalid num of fields");
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_JNI_SQL_NULL, "empty sql string");
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_JNI_FETCH_END, "fetch to the end of resultSet");
diff --git a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBErrorNumbers.java b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBErrorNumbers.java
index 2003229a3a975d32705f75a1e86b6b4235343ab3..3ae8696f7d3931160ab55f31064839b33a9ceecd 100644
--- a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBErrorNumbers.java
+++ b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBErrorNumbers.java
@@ -25,7 +25,7 @@ public class TSDBErrorNumbers {
     public static final int ERROR_UNSUPPORTED_ENCODING = 0x2352; // Unsupported encoding
 
     public static final int ERROR_JNI_TDENGINE_ERROR = 0x2353;   // internal error of database
-    public static final int ERROR_JNI_CONNECTION_NULL = 0x2354;  // JNI connection already closed
+    public static final int ERROR_JNI_CONNECTION_NULL = 0x2354;  // JNI connection is NULL
     public static final int ERROR_JNI_RESULT_SET_NULL = 0x2355;  // invalid JNI result set
     public static final int ERROR_JNI_NUM_OF_FIELDS_0 = 0x2356;  // invalid num of fields
     public static final int ERROR_JNI_SQL_NULL = 0x2357;        // empty sql string
diff --git a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBJNIConnector.java b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBJNIConnector.java
index 68905938c3507b2873d798b591d81cd222f2bfb6..f3c4e025798e8e3fd8db0e5c1a1b25aa6fea3dc7 100755
--- a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBJNIConnector.java
+++ b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBJNIConnector.java
@@ -102,7 +102,7 @@ public class TSDBJNIConnector {
 
         this.taos = this.connectImp(host, port, dbName, user, password);
         if (this.taos == TSDBConstants.JNI_NULL_POINTER) {
-            throw TSDBError.createSQLException(this.getErrCode(0l), this.getErrMsg(0L));
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_JNI_CONNECTION_NULL);
         }
         // invoke connectImp only here
         taosInfo.conn_open_increment();
@@ -273,7 +273,7 @@ public class TSDBJNIConnector {
     public void closeConnection() throws SQLException {
         int code = this.closeConnectionImp(this.taos);
         if (code < 0) {
-            throw TSDBError.createSQLException(this.getErrCode(0l), this.getErrMsg(0L));
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_JNI_CONNECTION_NULL);
         } else if (code == 0) {
             this.taos = TSDBConstants.JNI_NULL_POINTER;
         } else {
diff --git a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/ConnectWrongDatabaseTest.java b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/ConnectWrongDatabaseTest.java
index 3fcdcf55fe5f133eeff89afc5f298c8ef2c7e1f7..875368d17e0114f80e72fc45f25a2352131dcd72 100644
--- a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/ConnectWrongDatabaseTest.java
+++ b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/ConnectWrongDatabaseTest.java
@@ -16,7 +16,7 @@ public class ConnectWrongDatabaseTest {
         } catch (ClassNotFoundException e) {
             e.printStackTrace();
         } catch (SQLException e) {
-            Assert.assertEquals(-2147482749, e.getErrorCode());
+            Assert.assertEquals(-2, e.getErrorCode());
         }
     }