diff --git a/Ubiquitous/XiZi_IIoT/board/xidatong-riscv64/third_party_driver/ethernet/connect_w5500.c b/Ubiquitous/XiZi_IIoT/board/xidatong-riscv64/third_party_driver/ethernet/connect_w5500.c
index 070bcefc3..c48f5944f 100644
--- a/Ubiquitous/XiZi_IIoT/board/xidatong-riscv64/third_party_driver/ethernet/connect_w5500.c
+++ b/Ubiquitous/XiZi_IIoT/board/xidatong-riscv64/third_party_driver/ethernet/connect_w5500.c
@@ -23,7 +23,7 @@ extern void spi_deselete_cs(void);
 
 // global configurations for w5500 tcp connection
 const uint32_t socket_tcp = 0;
-const uint32_t g_wiznet_buf_size = 2048;
+const uint32_t g_wiznet_buf_size = 256;
 
 static wiz_NetInfo g_wiz_netinfo = {.mac = {0x00, 0x08, 0xdc, 0x11, 0x11, 0x11},
                                     .ip = {192, 168, 31, 13},
@@ -325,23 +325,24 @@ void wiz_client_op_test(int argc, char *argv[]) {
   }
   KPrintf("[W5500 Client] wiz client to %d.%d.%d.%d:%d\n", ip[0], ip[1], ip[2],
           ip[3], port);
-  uint8_t buf[g_wiznet_buf_size];
-  memset(buf, '\0', g_wiznet_buf_size);
-  memcpy(buf, argv[3], strlen(argv[3]));
-  KPrintf("[W5500 Client] BUFFER: %s\n", buf);
+  uint8_t send_buf[g_wiznet_buf_size];
+  uint8_t recv_buf[g_wiznet_buf_size];
+  memset(send_buf, '\0', g_wiznet_buf_size);
+  memset(recv_buf, '\0', g_wiznet_buf_size);
+  memcpy(send_buf, argv[3], strlen(argv[3]));
+  KPrintf("[W5500 Client] BUFFER: %s\n", send_buf);
   while (1) {
-    int ret =
-        wiz_client_op(client_sock, buf, g_wiznet_buf_size, ip, port, SEND_DATA);
+    int ret = wiz_client_op(client_sock, send_buf, g_wiznet_buf_size, ip, port,
+                            SEND_DATA);
     if (ret < 0) {
       KPrintf("[W5500] Client Op Failed.\n");
     }
     MdelayKTask(10);
-    memset(buf, '\0', g_wiznet_buf_size);
     // waiting for a responding.
-    ret =
-        wiz_client_op(client_sock, buf, g_wiznet_buf_size, ip, port, RECV_DATA);
+    ret = wiz_client_op(client_sock, recv_buf, g_wiznet_buf_size, ip, port,
+                        RECV_DATA);
     if (ret > 0) {
-      KPrintf("received msg: %s\n", buf);
+      KPrintf("received msg: %s\n", recv_buf);
       break;
     }
   }