diff --git a/components/drivers/spi/qspi_core.c b/components/drivers/spi/qspi_core.c
index ca2cba0ababfbac47e756ff79ca28ebd7cb4bb0d..973dc05f4cf809811e6b150513901e6a97131339 100644
--- a/components/drivers/spi/qspi_core.c
+++ b/components/drivers/spi/qspi_core.c
@@ -5,7 +5,8 @@
  *
  * Change Logs:
  * Date           Author       Notes
- * 2018-11-16     zylx      first version.
+ * 2018-11-16     zylx         first version.
+ * 2022-04-28     Bangju Jin   fix bug in rt_qspi_send
  */
 
 #include <drivers/spi.h>
@@ -186,7 +187,7 @@ rt_err_t rt_qspi_send(struct rt_qspi_device *device, const void *send_buf, rt_si
     RT_ASSERT(length != 0);
 
     struct rt_qspi_message message;
-    char *ptr = (char *)send_buf;
+    unsigned char *ptr = (unsigned char *)send_buf;
     rt_size_t  count = 0;
     rt_err_t result = 0;