diff --git a/tools/converter.py b/tools/converter.py
index 1f0f568cb963231d9f6435f2d7833cda773567d9..9e7973a94ba328b63d5191ee4f739bf12dc7a76f 100644
--- a/tools/converter.py
+++ b/tools/converter.py
@@ -39,6 +39,7 @@ from common import StringFormatter
 # common definitions
 ################################
 BUILD_OUTPUT_DIR = 'build'
+BUILD_DOWNLOADS_DIR = BUILD_OUTPUT_DIR + '/downloads'
 PHONE_DATA_DIR = "/data/local/tmp/mace_run"
 MODEL_OUTPUT_DIR_NAME = 'model'
 MODEL_HEADER_DIR_PATH = 'include/mace/public'
@@ -536,36 +537,41 @@ def print_configuration(flags, configs):
     MaceLogger.summary(StringFormatter.table(header, data, title))
 
 
-def download_model_files(model_file_path,
-                         model_output_dir,
-                         weight_file_path=""):
-    MaceLogger.info("Downloading model, please wait ...")
-    if model_file_path.startswith("http://") or \
-            model_file_path.startswith("https://"):
-        model_file = model_output_dir + "/model.pb"
-        urllib.urlretrieve(model_file_path, model_file)
-
-    if weight_file_path.startswith("http://") or \
-            weight_file_path.startswith("https://"):
-        weight_file = model_output_dir + "/model.caffemodel"
-        urllib.urlretrieve(weight_file_path, weight_file)
-    MaceLogger.info("Model downloaded successfully.")
-
+def get_model_files(model_file_path,
+                    model_sha256_checksum,
+                    model_output_dir,
+                    weight_file_path="",
+                    weight_sha256_checksum=""):
+    model_file = model_file_path
+    weight_file = weight_file_path
 
-def get_model_files_path(model_file_path,
-                         model_output_dir,
-                         weight_file_path=""):
     if model_file_path.startswith("http://") or \
             model_file_path.startswith("https://"):
-        model_file = model_output_dir + "/model.pb"
-    else:
-        model_file = model_file_path
+        model_file = model_output_dir + "/" + md5sum(model_file_path) + ".pb"
+        if not os.path.exists(model_file) or \
+                sha256_checksum(model_file) != model_sha256_checksum:
+            MaceLogger.info("Downloading model, please wait ...")
+            urllib.urlretrieve(model_file_path, model_file)
+            MaceLogger.info("Model downloaded successfully.")
+
+    if sha256_checksum(model_file) != model_sha256_checksum:
+        MaceLogger.error(ModuleName.MODEL_CONVERTER,
+                         "model file sha256checksum not match")
 
     if weight_file_path.startswith("http://") or \
             weight_file_path.startswith("https://"):
-        weight_file = model_output_dir + "/model.caffemodel"
-    else:
-        weight_file = weight_file_path
+        weight_file = \
+            model_output_dir + "/" + md5sum(weight_file_path) + ".caffemodel"
+        if not os.path.exists(weight_file) or \
+                sha256_checksum(weight_file) != weight_sha256_checksum:
+            MaceLogger.info("Downloading model weight, please wait ...")
+            urllib.urlretrieve(weight_file_path, weight_file)
+            MaceLogger.info("Model weight downloaded successfully.")
+
+    if weight_file:
+        if sha256_checksum(weight_file) != weight_sha256_checksum:
+            MaceLogger.error(ModuleName.MODEL_CONVERTER,
+                             "weight file sha256checksum not match")
 
     return model_file, weight_file
 
@@ -578,6 +584,8 @@ def convert_model(configs):
     elif os.path.exists(os.path.join(BUILD_OUTPUT_DIR, library_name)):
         sh.rm("-rf", os.path.join(BUILD_OUTPUT_DIR, library_name))
     os.makedirs(os.path.join(BUILD_OUTPUT_DIR, library_name))
+    if not os.path.exists(BUILD_DOWNLOADS_DIR):
+        os.makedirs(BUILD_DOWNLOADS_DIR)
 
     model_output_dir = \
         '%s/%s/%s' % (BUILD_OUTPUT_DIR, library_name, MODEL_OUTPUT_DIR_NAME)
@@ -609,38 +617,12 @@ def convert_model(configs):
         model_config = configs[YAMLKeyword.models][model_name]
         runtime = model_config[YAMLKeyword.runtime]
 
-        # Create model build directory
-        model_path_digest = md5sum(
-            model_config[YAMLKeyword.model_file_path])
-
-        model_output_base_dir = "%s/%s/%s/%s/%s" % (
-            BUILD_OUTPUT_DIR, library_name, BUILD_TMP_DIR_NAME,
-            model_name, model_path_digest)
-
-        if os.path.exists(model_output_base_dir):
-            sh.rm("-rf", model_output_base_dir)
-        os.makedirs(model_output_base_dir)
-
-        download_model_files(
-            model_config[YAMLKeyword.model_file_path],
-            model_output_base_dir,
-            model_config[YAMLKeyword.weight_file_path])
-
-        model_file_path, weight_file_path = get_model_files_path(
+        model_file_path, weight_file_path = get_model_files(
             model_config[YAMLKeyword.model_file_path],
-            model_output_base_dir,
-            model_config[YAMLKeyword.weight_file_path])
-
-        if sha256_checksum(model_file_path) != \
-                model_config[YAMLKeyword.model_sha256_checksum]:
-            MaceLogger.error(ModuleName.MODEL_CONVERTER,
-                             "model file sha256checksum not match")
-
-        if weight_file_path:
-            if sha256_checksum(weight_file_path) != \
-                    model_config[YAMLKeyword.weight_sha256_checksum]:
-                MaceLogger.error(ModuleName.MODEL_CONVERTER,
-                                 "weight file sha256checksum not match")
+            model_config[YAMLKeyword.model_sha256_checksum],
+            BUILD_DOWNLOADS_DIR,
+            model_config[YAMLKeyword.weight_file_path],
+            model_config[YAMLKeyword.weight_sha256_checksum])
 
         data_type = model_config[YAMLKeyword.data_type]
         # TODO(liuqi): support multiple subgraphs
@@ -1068,10 +1050,12 @@ def run_specific_target(flags, configs, target_abi,
                 linkshared=linkshared,
             )
             if flags.validate:
-                model_file_path, weight_file_path = get_model_files_path(
+                model_file_path, weight_file_path = get_model_files(
                     model_config[YAMLKeyword.model_file_path],
-                    model_output_base_dir,
-                    model_config[YAMLKeyword.weight_file_path])
+                    model_config[YAMLKeyword.model_sha256_checksum],
+                    BUILD_DOWNLOADS_DIR,
+                    model_config[YAMLKeyword.weight_file_path],
+                    model_config[YAMLKeyword.weight_sha256_checksum])
 
                 sh_commands.validate_model(
                     abi=target_abi,