diff --git a/hugegraph-core/src/main/java/com/baidu/hugegraph/util/ConfigUtil.java b/hugegraph-core/src/main/java/com/baidu/hugegraph/util/ConfigUtil.java
index 5dea629106..b99ed45870 100644
--- a/hugegraph-core/src/main/java/com/baidu/hugegraph/util/ConfigUtil.java
+++ b/hugegraph-core/src/main/java/com/baidu/hugegraph/util/ConfigUtil.java
@@ -110,15 +110,17 @@ public static Map<String, String> scanGraphsDir(String graphsDirPath) {
 
     public static String writeToFile(String dir, String graphName,
                                      HugeConfig config) {
-        E.checkArgument(FileUtils.getFile(dir).exists(),
-                        "The directory '%s' must exist", dir);
-        String fileName = Paths.get(dir, graphName + CONF_SUFFIX).toString();
+        File file = FileUtils.getFile(dir);
+        E.checkArgument(file.exists(),
+            "The directory '%s' must exist", dir);
+        String fileName = file.getPath() + File.separator + graphName + CONF_SUFFIX;
         try {
-            config.save(new File(fileName));
+            File newFile = FileUtils.getFile(fileName);
+            config.save(newFile);
             LOG.info("Write HugeConfig to file: '{}'", fileName);
         } catch (ConfigurationException e) {
             throw new HugeException("Failed to write HugeConfig to file '%s'",
-                                    e, fileName);
+                e, fileName);
         }
 
         return fileName;