diff --git a/ds-wms-service/DS.Module.Core/Condition/ConditionHelper.cs b/ds-wms-service/DS.Module.Core/Condition/ConditionHelper.cs
index b88e9b40..37f2c3a0 100644
--- a/ds-wms-service/DS.Module.Core/Condition/ConditionHelper.cs
+++ b/ds-wms-service/DS.Module.Core/Condition/ConditionHelper.cs
@@ -56,13 +56,17 @@ namespace DS.Module.Core.Condition
                 switch (item.Operator)
                 {
                     case "equal":
-                        itemResult = valStr?.Equals(item.Value, StringComparison.OrdinalIgnoreCase) == true; break;
+                        itemResult = (valStr == null && item.Value == null) || valStr?.Equals(item.Value, StringComparison.OrdinalIgnoreCase) == true; break;
                     case "not_equal":
-                        itemResult = valStr?.Equals(item.Value, StringComparison.OrdinalIgnoreCase) != true; break;
+                        itemResult = (valStr != null || item.Value != null) && valStr?.Equals(item.Value, StringComparison.OrdinalIgnoreCase) != true; break;
                     case "contains":
                         itemResult = valStr?.Contains(item.Value, StringComparison.OrdinalIgnoreCase) == true; break;
                     case "not_contain":
                         itemResult = valStr?.Contains(item.Value, StringComparison.OrdinalIgnoreCase) != true; break;
+                    case "empty":
+                        itemResult = string.IsNullOrWhiteSpace(valStr) == true; break;
+                    case "not_empty":
+                        itemResult = string.IsNullOrWhiteSpace(valStr) != true; break;
                     case "start_with":
                         itemResult = valStr?.StartsWith(item.Value, StringComparison.OrdinalIgnoreCase) == true; break;
                     case "end_with":