diff --git a/java/tsfile/src/main/java/org/apache/tsfile/utils/ReadWriteIOUtils.java b/java/tsfile/src/main/java/org/apache/tsfile/utils/ReadWriteIOUtils.java
index 88f1388d5..f5e3e475d 100644
--- a/java/tsfile/src/main/java/org/apache/tsfile/utils/ReadWriteIOUtils.java
+++ b/java/tsfile/src/main/java/org/apache/tsfile/utils/ReadWriteIOUtils.java
@@ -431,7 +431,7 @@ public static int writeVar(String s, ByteBuffer buffer) {
       return ReadWriteForEncodingUtils.writeVarInt(NO_BYTE_TO_READ, buffer);
     }
     int len = 0;
-    byte[] bytes = s.getBytes();
+    byte[] bytes = s.getBytes(TSFileConfig.STRING_CHARSET);
     len += ReadWriteForEncodingUtils.writeVarInt(bytes.length, buffer);
     buffer.put(bytes);
     len += bytes.length;