diff --git a/armsrc/Standalone/hf_mfcsim.c b/armsrc/Standalone/hf_mfcsim.c
index 811542d49..403793b71 100644
--- a/armsrc/Standalone/hf_mfcsim.c
+++ b/armsrc/Standalone/hf_mfcsim.c
@@ -30,56 +30,47 @@
  * It requires RDV4 hardware (for flash and battery).
  *
  * On entering stand-alone mode, this module will start simulating.
- * Data is read from bin dump file uploaded to flash memory (hf_mfcsim_dump.bin).
+ * Data is read from bin dump file uploaded to flash memory (hf_mfcsim_dump_xx.bin).
  * Only support mifare classic 1k
  *
- * LEDs:
- * - LED A: initializing
- * - LED B: simulating
- * - LED C blinking: data transmiting
- *
  * To upload input file (eml format) to flash:
- * - mem spiffs upload -s <filename> -d hf_mfcsim_dump.bin
+ * - mem spiffs upload -s <filename> -d hf_mfcsim_dump_xx.bin (Notes: xx is form 01 to 15)
  * To delete the input file from flash:
- * - mem spiffs remove -f hf_mfcsim_dump.bin
- *
+ * - mem spiffs remove -f hf_mfcsim_dump_xx.bin (Notes: xx is form 01 to 15)
+ * 
  */
 
-#define HF_MFCSIM_INPUTFILE_SIM         "hf_mfcsim_dump.bin"
+#define HF_MFCSIM_DUMPFILE_SIM         "hf_mfcsim_dump_%02d.bin"
 #define DUMP_SIZE                       1024
 
-static uint8_t uid[10];
+static char cur_dump_file[22] = {0};
 
-static bool ecfill_from_file(char *inputfile) {
-
-    if (exists_in_spiffs(inputfile)) {
-        uint32_t size = size_in_spiffs(inputfile);
-        uint8_t *mem = BigBuf_malloc(size);
-        if (!mem) {
-            Dbprintf(_RED_("No memory！"));
-            return false;
-        }
-
-        //read dumpfile
-        Dbprintf(_YELLOW_("Found dump file %s"), inputfile);
-        rdv40_spiffs_read_as_filetype(inputfile, mem, size, RDV40_SPIFFS_SAFETY_SAFE);
+static bool ecfill_from_file(char *dumpfile) {
 
+    if (exists_in_spiffs(dumpfile)) {
         //check dumpfile size
-        Dbprintf(_YELLOW_("File size is %d"), size);
+        uint32_t size = size_in_spiffs(dumpfile);
         if (size != DUMP_SIZE) {
-            Dbprintf(_RED_("Only support Mifare Classic 1K! Please check the dumpfile"));
+            Dbprintf(_RED_("File Size: %dB  The dump file size is incorrect! Only support Mifare Classic 1K! Please check it."));
             BigBuf_free();
             return false;
         }
 
-        //load the dump into emulator memory
-        Dbprintf(_YELLOW_("Read card data from input file"));
+        uint8_t *mem = BigBuf_malloc(size);
+        if (!mem) {
+            Dbprintf(_RED_("No memory!"));
+            return false;
+        }
+
+        //read and load dump file
+        if (DBGLEVEL >= DBG_INFO) Dbprintf(_YELLOW_("Found dump file %s. Uploading to emulator memory..."), dumpfile);
+        rdv40_spiffs_read_as_filetype(dumpfile, mem, size, RDV40_SPIFFS_SAFETY_SAFE);
+        emlClearMem();
         emlSetMem(mem, 0, MIFARE_1K_MAXBLOCK);
-        Dbprintf(_YELLOW_("Uploaded to emulator memory"));
         BigBuf_free_keep_EM();
         return true;
     } else {
-        Dbprintf(_RED_("no input file %s"), inputfile);
+        Dbprintf(_RED_("Dump file %s not found!"), dumpfile);
         return false;
     }
     return false;//Shouldn't be here
@@ -90,30 +81,36 @@ void ModInfo(void) {
 }
 
 void RunMod(void) {
+    //initializing
     StandAloneMode();
     FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+    rdv40_spiffs_lazy_mount();
     Dbprintf(_YELLOW_("Standalone mode MFCSIM started!"));
 
-    LED_A_ON();
-    emlClearMem();
-    Dbprintf(_YELLOW_("Emulator memory initialized"));
-    rdv40_spiffs_lazy_mount();
-    if (!ecfill_from_file(HF_MFCSIM_INPUTFILE_SIM)) {
-        Dbprintf(_RED_("Load data failed!"));
-        return;
+    bool flag_has_dumpfile = false;
+    for (int i = 1;; i++) {
+        if (i > 15) {
+            if (flag_has_dumpfile) i = 1; //Next loop!
+            else break;//No dump,Exit!
+        }
+        LED(i, 1000);
+        emlClearMem();
+
+        sprintf(cur_dump_file, HF_MFCSIM_DUMPFILE_SIM, i);
+        Dbprintf(_YELLOW_("[Slot: %d] Try to load dump file: %s"), i, cur_dump_file);
+        if (!ecfill_from_file(cur_dump_file)) {
+            Dbprintf(_YELLOW_("[Slot: %d] Dump load Failed, Next one!"), i);
+            continue;
+        }
+        flag_has_dumpfile = true;
+
+        Dbprintf(_YELLOW_("[Slot: %d] Simulation start, Press button to change next card."), i);
+        uint16_t simflags = FLAG_UID_IN_EMUL | FLAG_MF_1K;
+        Mifare1ksim(simflags, 0, NULL, 0, 0);
+        Dbprintf(_YELLOW_("[Slot: %d] Simulation end, Change to next card!"), i);
     }
-    Dbprintf(_YELLOW_("Emulator memory filled, simulation ready to start."));
-    Dbprintf(_YELLOW_("Press button to abort simulation at anytime."));
-
-    SpinOff(1000);
-
-    LED_B_ON();
-    Dbprintf(_YELLOW_("Simulation start!"));
-    uint16_t simflags = FLAG_UID_IN_EMUL | FLAG_MF_1K;
-    Mifare1ksim(simflags, 0, uid, 0, 0);
-
-    Dbprintf(_YELLOW_("Simulation end!"));
-    LEDsoff();
+    Dbprintf("No dump file found, Exit!");
+    return;
 }