diff --git a/smtweb-system/sw-system-bpm/src/main/java/cc/smtweb/system/bpm/web/engine/dynPage/DynPageHelper.java b/smtweb-system/sw-system-bpm/src/main/java/cc/smtweb/system/bpm/web/engine/dynPage/DynPageHelper.java
index b2472f2..cce2438 100644
--- a/smtweb-system/sw-system-bpm/src/main/java/cc/smtweb/system/bpm/web/engine/dynPage/DynPageHelper.java
+++ b/smtweb-system/sw-system-bpm/src/main/java/cc/smtweb/system/bpm/web/engine/dynPage/DynPageHelper.java
@@ -142,7 +142,7 @@ public class DynPageHelper {
             }
         }
         for (String s : setFixedFilter) {
-            args.put(s, params.get(s));
+            args.put(s, MapUtil.readString(params, s, ""));
         }
         return new SqlNamedPara(sql.toString(), args);
     }