diff --git a/datachecker-extract/src/main/java/org/opengauss/datachecker/extract/task/functional/SimpleTypeHandlerFactory.java b/datachecker-extract/src/main/java/org/opengauss/datachecker/extract/task/functional/SimpleTypeHandlerFactory.java
index 1c0e2c0d272761e3618853e071f164291f140a17..177934447e6597631b7768da6c65216a19e6b586 100644
--- a/datachecker-extract/src/main/java/org/opengauss/datachecker/extract/task/functional/SimpleTypeHandlerFactory.java
+++ b/datachecker-extract/src/main/java/org/opengauss/datachecker/extract/task/functional/SimpleTypeHandlerFactory.java
@@ -488,7 +488,10 @@ public class SimpleTypeHandlerFactory {
      * @return SimpleTypeHandler
      */
     public SimpleTypeHandler createOgBitHandler() {
-        return (rs, columnLabel) -> HexUtil.binaryToHex(rs.getString(columnLabel));
+        return (rs, columnLabel) -> {
+            String bit = rs.getString(columnLabel);
+            return rs.wasNull() ? NULL : HexUtil.binaryToHex(bit);
+        };
     }
 
     /**