diff --git a/rt-thread-version/rt-thread-standard/programming-manual/device/i2c/i2c.md b/rt-thread-version/rt-thread-standard/programming-manual/device/i2c/i2c.md
index 50f5842fcf877ef28656997f2a9f49fbe4005676..a31e2f1f44bddcca0559f27ca738eb20ead09a26 100644
--- a/rt-thread-version/rt-thread-standard/programming-manual/device/i2c/i2c.md
+++ b/rt-thread-version/rt-thread-standard/programming-manual/device/i2c/i2c.md
@@ -180,15 +180,20 @@ static rt_err_t write_reg(struct rt_i2c_bus_device *bus, rt_uint8_t reg, rt_uint
 {
     rt_uint8_t buf[3];
     struct rt_i2c_msg msgs;
+    rt_uint32_t buf_size = 1;
 
     buf[0] = reg; //cmd
-    buf[1] = data[0];
-    buf[2] = data[1];
+    if (data != RT_NULL)
+    {
+        buf[1] = data[0];
+        buf[2] = data[1];
+        buf_size = 3
+    }
 
     msgs.addr = AHT10_ADDR;
     msgs.flags = RT_I2C_WR;
     msgs.buf = buf;
-    msgs.len = 3;
+    msgs.len = buf_size;
 
     /* 调用I2C设备接口传输数据 */
     if (rt_i2c_transfer(bus, &msgs, 1) == 1)
@@ -226,7 +231,7 @@ static void read_temp_humi(float *cur_temp, float *cur_humi)
 {
     rt_uint8_t temp[6];
 
-    write_reg(i2c_bus, AHT10_GET_DATA, 0);      /* 发送命令 */
+    write_reg(i2c_bus, AHT10_GET_DATA, RT_NULL);      /* 发送命令 */
     rt_thread_mdelay(400);
     read_regs(i2c_bus, 6, temp);                /* 获取传感器数据 */