diff --git a/demos/src/demo_sm2_public_key_digest.c b/demos/src/demo_sm2_public_key_digest.c
new file mode 100644
index 00000000..e1c01ac0
--- /dev/null
+++ b/demos/src/demo_sm2_public_key_digest.c
@@ -0,0 +1,41 @@
+/*
+ *  Copyright 2014-2022 The GmSSL Project. All Rights Reserved.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the License); you may
+ *  not use this file except in compliance with the License.
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <gmssl/mem.h>
+#include <gmssl/sm2.h>
+#include <gmssl/sm3.h>
+
+int main(void){
+	SM2_KEY sm2_key;
+	uint8_t dgst[32];
+	int i;
+
+	printf("Read SM2 public key file (PEM) from stdin ...\n");
+
+	if (sm2_public_key_info_from_pem(&sm2_key, stdin) != 1) {
+		fprintf(stderr, "error\n");
+		return 1;
+	}
+
+	if (sm2_public_key_digest(&sm2_key, dgst) != 1) {
+		fprintf(stderr, "error\n");
+		return 1;
+	}
+	
+	for (i = 0; i < sizeof(dgst); i++) {
+		printf("%02x", dgst[i]);
+	}
+	printf("\n");
+	
+	gmssl_secure_clear(&sm2_key, sizeof(sm2_key));
+	return 0;
+}