diff --git a/cap/zx297520v3/sources/meta-zxic-custom/recipes-lynq/lynq-qser-gnss-demo/files/lynq-qser-gnss-demo.cpp b/cap/zx297520v3/sources/meta-zxic-custom/recipes-lynq/lynq-qser-gnss-demo/files/lynq-qser-gnss-demo.cpp
index d3d8e89..c8fcda2 100755
--- a/cap/zx297520v3/sources/meta-zxic-custom/recipes-lynq/lynq-qser-gnss-demo/files/lynq-qser-gnss-demo.cpp
+++ b/cap/zx297520v3/sources/meta-zxic-custom/recipes-lynq/lynq-qser-gnss-demo/files/lynq-qser-gnss-demo.cpp
@@ -49,6 +49,7 @@
         printf("=========gnss main=========\n");
         user_help();
         scanf("%d", &opt);
+        while(getchar()!='\n');
         switch (opt)
         {
         case -1:
@@ -157,6 +158,7 @@
             printf("=========delete aiding data type=========\n");
             delete_type();
             scanf("%d", &opt_1);
+            while(getchar()!='\n');
             switch(opt_1)
             {
             case 0:
@@ -189,6 +191,11 @@
                 ptr = DELETE_ALL;//cold
                 break;
             }
+            default:
+            {
+                printf("input error\n");
+                return -1;
+            }
             }
             ret = qser_Gnss_Delete_Aiding_Data(ph_gnss,ptr);
             if(ret < 0)
@@ -267,6 +274,11 @@
             printf("qser_Gnss_Server_Configuration ssuccess\n");
             break;
         }
+        default:
+        {
+            printf("input error,please re-enter\n");
+            break;
+        }
         }
     }
     return 0;