diff --git a/mongo-plus-core/src/main/java/com/anwen/mongo/mapping/SimpleTypeHolder.java b/mongo-plus-core/src/main/java/com/anwen/mongo/mapping/SimpleTypeHolder.java
index 20250aa44c32714c0ec1c257256268515db1dc52..7f82fc6a409ed33f01e1e66be064e078e8585d51 100644
--- a/mongo-plus-core/src/main/java/com/anwen/mongo/mapping/SimpleTypeHolder.java
+++ b/mongo-plus-core/src/main/java/com/anwen/mongo/mapping/SimpleTypeHolder.java
@@ -2,6 +2,7 @@ package com.anwen.mongo.mapping;
 
 import com.anwen.mongo.toolkit.Assert;
 
+import java.math.BigDecimal;
 import java.util.*;
 
 /**
@@ -43,6 +44,7 @@ public class SimpleTypeHolder {
         defaults.add(Locale.class);
         defaults.add(Class.class);
         defaults.add(Enum.class);
+        defaults.add(BigDecimal.class);
         DEFAULTS = Collections.unmodifiableSet(defaults);
     }