diff --git a/components/net/at/src/at_client.c b/components/net/at/src/at_client.c
index 4eb2c05..6733736 100644
--- a/components/net/at/src/at_client.c
+++ b/components/net/at/src/at_client.c
@@ -610,7 +610,8 @@ at_client_t at_client_get(const char *dev_name)
 
     for (idx = 0; idx < AT_CLIENT_NUM_MAX; idx++)
     {
-        if (rt_strcmp(at_client_table[idx].device->parent.name, dev_name) == 0)
+        if (at_client_table[idx].device && \
+            (rt_strcmp(at_client_table[idx].device->parent.name, dev_name) == 0))
         {
             return &at_client_table[idx];
         }