diff --git a/hypervisor/include/lib/rtl.h b/hypervisor/include/lib/rtl.h
index 6ba21cc5e..41d545854 100644
--- a/hypervisor/include/lib/rtl.h
+++ b/hypervisor/include/lib/rtl.h
@@ -24,7 +24,6 @@ void udelay(uint32_t us);
 void *memchr(const void *void_s, int32_t c, size_t n);
 int32_t strcmp(const char *s1_arg, const char *s2_arg);
 int32_t strncmp(const char *s1_arg, const char *s2_arg, size_t n_arg);
-char *strcpy_s(char *d_arg, size_t dmax, const char *s_arg);
 char *strncpy_s(char *d_arg, size_t dmax, const char *s_arg, size_t slen_arg);
 char *strchr(char *s_arg, char ch);
 size_t strnlen_s(const char *str_arg, size_t maxlen_arg);
diff --git a/hypervisor/lib/string.c b/hypervisor/lib/string.c
index 8c51b1ca6..da0d1e2ad 100644
--- a/hypervisor/lib/string.c
+++ b/hypervisor/lib/string.c
@@ -172,79 +172,6 @@ char *strchr(char *s_arg, char ch)
 	return ((*s) != '\0') ? s : NULL;
 }
 
-/**
- *strcpy_s
- *
- * description:
- *    This function copies the string pointed to by s to a buffer
- *    pointed by d.
- *
- * input:
- *    d        pointer to dest buffer.
- *
- *    dmax     maximum length of dest buffer
- *
- *    s        pointer to the source string
- *
- * return value:
- *    dest      pointer to dest string if string is copied
- *              successfully,or else return null.
- *
- * notes:
- *    1) both d and s shall not be null pointers.
- *    2) dmax shall not 0.
- */
-char *strcpy_s(char *d_arg, size_t dmax, const char *s_arg)
-{
-	char *d = d_arg;
-	const char *s = s_arg;
-	char *dest_base;
-	size_t dest_avail;
-	uint64_t overlap_guard;
-
-	if ((s == NULL) || (d == NULL) || (dmax == 0U)) {
-		pr_err("%s: invalid src, dest buffer or length.", __func__);
-		return NULL;
-	}
-
-	if (s == d) {
-		return d;
-	}
-
-	overlap_guard = (uint64_t)((d > s) ? (d - s - 1) : (s - d - 1));
-
-	dest_avail = dmax;
-	dest_base = d;
-
-	while (dest_avail > 0U) {
-		if (overlap_guard == 0U) {
-			pr_err("%s: overlap happened.", __func__);
-			d--;
-			*d = '\0';
-			return NULL;
-		}
-
-		*d = *s;
-		if (*d == '\0') {
-			return dest_base;
-		}
-
-		d++;
-		s++;
-		dest_avail--;
-		overlap_guard--;
-	}
-
-	pr_err("%s: dest buffer has no enough space.", __func__);
-
-	/*
-	 * to avoid a string that is not
-	 * null-terminated in dest buffer
-	 */
-	dest_base[dmax - 1] = '\0';
-	return NULL;
-}
-
 /*
  * strncpy_s
  *