diff --git a/include/HShellLex.h b/include/HShellLex.h
index 19420ac..7121fa3 100644
--- a/include/HShellLex.h
+++ b/include/HShellLex.h
@@ -12,6 +12,13 @@ typedef uint8_t HShellLenType;
 
 // 是否使用密码
 #define HSHELL_USE_PASSWORD
+#define HSHELL_USER "hdroot"
+#define HSHELL_PASSWORD "hd456321;"
+
+// 是否使用上一次缓存
+#define HSHELL_USE_BACK_BUFFER
+#ifdef HSHELL_USE_BACK_BUFFER
+#endif
 
 ///< 可配置最多可注册回调多少个
 #ifndef HSHELL_CALL_MAX
@@ -25,7 +32,7 @@ typedef uint8_t HShellLenType;
 
 ///< 解析token参数的最大个数
 #ifndef HSHELL_CMD_TOKEN_MAX
-#define HSHELL_CMD_TOKEN_MAX 3
+#define HSHELL_CMD_TOKEN_MAX 4
 #endif
 
 ///< 打印帮助命令行长度多少换行
diff --git a/src/HShellLex.c b/src/HShellLex.c
index 6f76597..a961c22 100644
--- a/src/HShellLex.c
+++ b/src/HShellLex.c
@@ -41,11 +41,15 @@ struct __attribute__((packed)) ShellInfo {
 
 // 命令行缓存数据
 static HVECTOR_DEFINE(cmdBuffer_, HSHELL_CMD_LINE_BUFFER);
+#ifdef HSHELL_USE_BACK_BUFFER
+static HVECTOR_DEFINE(prevBuffer_, HSHELL_CMD_LINE_BUFFER);
+#endif
 static struct ShellInfo shellInfo_;
 
 
 static void PrintAllCmd() {
     uint16_t len = 0;
+    uint16_t pos = 10;
     for (int i = 0; i < HSHELL_CALL_MAX; ++i) {
         if (shellInfo_.shellCmd[i].match == NULL) {
             continue;
@@ -56,10 +60,12 @@ static void PrintAllCmd() {
                 continue;
             }
 
-            HSHELL_PRINTF("%s\t", (const char *)shellInfo_.shellCmd[i].match[j].match);
-            len += shellInfo_.shellCmd[i].match[j].matchLen;
-            if (len >= HSHELL_CMD_LINE_NUM) {
+            pos = pos > shellInfo_.shellCmd[i].match[j].matchLen ? pos : shellInfo_.shellCmd[i].match[j].matchLen;
+            HSHELL_PRINTF("%-*s ", pos, (const char *)shellInfo_.shellCmd[i].match[j].match);
+            len += pos;
+            if (len >= 80) {
                 HSHELL_PRINTF("\r\n");
+                pos = 10;
                 len = 0;
             }
         }
@@ -86,15 +92,18 @@ static void ShellParse()
     if (shellInfo_.password == 0 || shellInfo_.userName == 0) {
         shellInfo_.needPrint = 1;
 
+        LogD("password[%d] userName[%d], data[%s]", shellInfo_.password, shellInfo_.userName, shellInfo_.cmdTokens[0].str);
         // 这个状态下说明用户名输入错误, 无论输入什么都是失败
         if (shellInfo_.password == 1 && shellInfo_.userName == 0) {
             shellInfo_.password = 0;
             return ;
         }
 
+#define _ICONV(name) name, sizeof(name) - 1
+#define ICONV(name) _ICONV(name)
         // 输入用户名
         if (shellInfo_.userName == 0) {
-            if (HShellDiffString(shellInfo_.cmdTokens, len, 0, "hdroot", 6, 0) == 0) {
+            if (HShellDiffString(shellInfo_.cmdTokens, len, 0, ICONV(HSHELL_USER), 0) == 0) {
                 // 用户名错误, 给输入假的密码机会
                 shellInfo_.password = 1;
                 return ;
@@ -105,7 +114,7 @@ static void ShellParse()
         }
 
         if (shellInfo_.password == 0) {
-            if (HShellDiffString(shellInfo_.cmdTokens, len, 0, "hd123", 5, 0) == 0) {
+            if (HShellDiffString(shellInfo_.cmdTokens, len, 0, ICONV(HSHELL_PASSWORD), 0) == 0) {
                 shellInfo_.userName = 0;
                 return ;
             }
@@ -114,6 +123,8 @@ static void ShellParse()
             return ;
         }
     }
+#undef _ICONV
+#undef ICONV
 #endif
 
     if (shellInfo_.cmdTokens[0].len == 1 && shellInfo_.cmdTokens[0].str[0] == '?') {
@@ -194,6 +205,21 @@ static void DeleteAfterByte() {
 }
 
 
+static void SwapPrevBuffer() {
+#ifdef HSHELL_USE_BACK_BUFFER
+    int len = HVectorGetUseByteLen(cmdBuffer_);
+    char *swapBuf[HSHELL_CMD_LINE_BUFFER];
+    memcpy(swapBuf, HVectorGetByteDataPtr(cmdBuffer_, 0), len);
+    HVectorClear(cmdBuffer_);
+    HVectorAddBytes(cmdBuffer_, (const uint8_t *)HVectorGetByteDataPtr(prevBuffer_, 0), HVectorGetUseByteLen(prevBuffer_));
+    HVectorClear(prevBuffer_);
+    HVectorAddBytes(prevBuffer_, (const uint8_t *)swapBuf, len);
+    shellInfo_.cursorPos = HVectorGetUseLen(cmdBuffer_);
+    shellInfo_.needPrint = 1;
+#endif
+}
+
+
 static void AddCmdData(uint8_t data) {
     enum eEscStaus {
         kEscNone,
@@ -235,6 +261,7 @@ static void AddCmdData(uint8_t data) {
         } return ;
         case 'A': // 上键
         case 'B': // 下键
+            SwapPrevBuffer();
             shellInfo_.escStatus = kEscNone;
             return ;
         case '3': {
@@ -348,6 +375,7 @@ uint8_t HShellDiffString(const HShellCmdToken *token, uint8_t tokenLen, uint8_t
     }
 
     if (token[index].len != strLen) {
+        LogD("token[%d] len[%d] is not equal strLen[%d]", index, token[index].len, strLen);
         return 0;
     }
 
@@ -446,6 +474,12 @@ void HShellRun() {
 
     HSHELL_PRINTFL("");
     ShellParse();
+#ifdef HSHELL_USE_BACK_BUFFER
+    if (HVectorEmpty(cmdBuffer_) == 0) {
+        HVectorClear(prevBuffer_);
+        HVectorAddBytes(prevBuffer_, (const uint8_t *)HVectorGetByteDataPtr(cmdBuffer_, 0), HVectorGetUseByteLen(cmdBuffer_));
+    }
+#endif
     HVectorClear(cmdBuffer_);
     HVectorSetData(cmdBuffer_, 0, '\0');
     PrintCmdLine();