diff --git a/core/src/main/local_storage/transformer/README.md b/core/src/main/local_storage/transformer/README.md
index 247609bf..4ac2dba5 100644
--- a/core/src/main/local_storage/transformer/README.md
+++ b/core/src/main/local_storage/transformer/README.md
@@ -80,7 +80,7 @@ public class Ipv4ToNum extends Transformer {
 
             //如果字段为空，返回 0
             if (oriValue==null) {
-                oriValue = "";
+                oriValue = "0.0.0.0";
             }
 
             String[] seq = oriValue.split("\\.");