diff --git a/apps/shell/include/shmsg.h b/apps/shell/include/shmsg.h
index b182db34..d9c172a2 100644
--- a/apps/shell/include/shmsg.h
+++ b/apps/shell/include/shmsg.h
@@ -47,6 +47,9 @@ extern "C" {
 #define SHELL_EXEC_COMMAND_BYTES    4
 #define CMD_EXEC_COMMAND            SHELL_EXEC_COMMAND" "
 #define CMD_EXEC_COMMAND_BYTES      (SHELL_EXEC_COMMAND_BYTES+1)
+#define CMD_EXIT_COMMAND            "exit"
+#define CMD_EXIT_COMMAND_BYTES      4
+#define CMD_EXIT_CODE_BASE_DEC      10
 
 #define CONSOLE_IOC_MAGIC   'c'
 #define CONSOLE_CONTROL_REG_USERTASK _IO(CONSOLE_IOC_MAGIC, 7)
diff --git a/apps/shell/src/shmsg.c b/apps/shell/src/shmsg.c
index 8329691b..320e60b4 100644
--- a/apps/shell/src/shmsg.c
+++ b/apps/shell/src/shmsg.c
@@ -44,7 +44,10 @@
 #include "shell_pri.h"
 #include "shcmd.h"
 
+#define CHAR_CTRL_C   '\x03'
+#define CHAR_CTRL_DEL '\x7F'
 
+#define VISIABLE_CHAR(ch) ((ch) > 0x1F && (ch) < 0x7F)
 
 char *GetCmdline(ShellCB *shellCB)
 {
@@ -202,7 +205,21 @@ void ParseEnterKey(OutputFunc outputFunc, ShellCB *shellCB)
         shellCB->shellBuf[shellCB->shellBufOffset] = '\0';
     }
 NOTIFY:
-    outputFunc("\n");
+    shellCB->shellBufOffset = 0;
+    ShellTaskNotify(shellCB);
+}
+
+void ParseCancelKey(OutputFunc outputFunc, ShellCB *shellCB)
+{
+    if ((shellCB == NULL) || (outputFunc == NULL)) {
+        return;
+    }
+
+    if (shellCB->shellBufOffset <= (SHOW_MAX_LEN - 1)) {
+        shellCB->shellBuf[0] = CHAR_CTRL_C;
+        shellCB->shellBuf[1] = '\0';
+    }
+
     shellCB->shellBufOffset = 0;
     ShellTaskNotify(shellCB);
 }
@@ -238,7 +255,7 @@ void ParseTabKey(OutputFunc outputFunc, ShellCB *shellCB)
 
 void ParseNormalChar(char ch, OutputFunc outputFunc, ShellCB *shellCB)
 {
-    if ((shellCB == NULL) || (outputFunc == NULL)) {
+    if ((shellCB == NULL) || (outputFunc == NULL) || !VISIABLE_CHAR(ch)) {
         return;
     }
 
@@ -256,7 +273,7 @@ void ShellCmdLineParse(char c, OutputFunc outputFunc, ShellCB *shellCB)
     const char ch = c;
     int ret;
 
-    if ((shellCB->shellBufOffset == 0) && (ch != '\n') && (ch != '\0')) {
+    if ((shellCB->shellBufOffset == 0) && (ch != '\n') && (ch != CHAR_CTRL_C) && (ch != '\0')) {
         (void)memset_s(shellCB->shellBuf, SHOW_MAX_LEN, 0, SHOW_MAX_LEN);
     }
 
@@ -265,8 +282,11 @@ void ShellCmdLineParse(char c, OutputFunc outputFunc, ShellCB *shellCB)
         case '\n': /* enter */
             ParseEnterKey(outputFunc, shellCB);
             break;
+        case CHAR_CTRL_C: /* ctrl + c */
+            ParseCancelKey(outputFunc, shellCB);
+            break;
         case '\b': /* backspace */
-        case 0x7F: /* delete(0x7F) */
+        case CHAR_CTRL_DEL: /* delete(0x7F) */
             ParseDeleteKey(outputFunc, shellCB);
             break;
         case '\t': /* tab */
@@ -358,6 +378,30 @@ void ChildExec(const char *cmdName, char *const paramArray[])
     }
 }
 
+int CheckExit(const char *cmdName, const CmdParsed *cmdParsed)
+{
+    int ret = 0;
+
+    if (strlen(cmdName) != CMD_EXIT_COMMAND_BYTES || strncmp(cmdName, CMD_EXIT_COMMAND, CMD_EXIT_COMMAND_BYTES) != 0) {
+        return 0;
+    }
+
+    if (cmdParsed->paramCnt > 1) {
+        printf("exit: too many arguments\n");
+        return -1;
+    }
+    if (cmdParsed->paramCnt == 1) {
+        char *p;
+        ret = strtol(cmdParsed->paramArray[0], &p, CMD_EXIT_CODE_BASE_DEC);
+        if (*p != '\0') {
+            printf("exit: bad number: %s\n", cmdParsed->paramArray[0]);
+            return -1;
+        }
+    }
+
+    exit(ret);
+}
+
 static void DoCmdExec(const char *cmdName, const char *cmdline, unsigned int len, const CmdParsed *cmdParsed)
 {
     int ret;
@@ -378,6 +422,9 @@ static void DoCmdExec(const char *cmdName, const char *cmdline, unsigned int len
             }
         }
     } else {
+        if (CheckExit(cmdName, cmdParsed) < 0) {
+            return;
+        }
         (void)syscall(__NR_shellexec, cmdName, cmdline);
     }
 }
@@ -535,7 +582,11 @@ static void ShellCmdProcess(ShellCB *shellCB)
         if (buf == NULL) {
             break;
         }
-
+        if (buf[0] == CHAR_CTRL_C) {
+            printf("^C");
+            buf[0] = '\n';
+        }
+        printf("\n");
         ExecCmdline(buf);
         ShellSaveHistoryCmd(buf, shellCB);
         shellCB->cmdMaskKeyLink = shellCB->cmdHistoryKeyLink;
diff --git a/kernel/common/console.c b/kernel/common/console.c
index 46cb1c8e..1eb47103 100644
--- a/kernel/common/console.c
+++ b/kernel/common/console.c
@@ -67,6 +67,9 @@ STATIC SPIN_LOCK_INIT(g_consoleSpin);
 #define CONSOLE_SEND_TASK_EXIT    0x04U
 #define CONSOLE_SEND_TASK_RUNNING 0x10U
 
+#define SHELL_ENTRY_NAME     "ShellEntry"
+#define SHELL_ENTRY_NAME_LEN 10
+
 CONSOLE_CB *g_console[CONSOLE_NUM];
 #define MIN(a, b) ((a) < (b) ? (a) : (b))
 
@@ -1440,15 +1443,31 @@ BOOL ConsoleEnable(VOID)
     return FALSE;
 }
 
+BOOL IsShellEntryRunning(UINT32 shellEntryId)
+{
+    LosTaskCB *taskCB;
+    if (shellEntryId == SHELL_ENTRYID_INVALID) {
+        return FALSE;
+    }
+    taskCB = OsGetTaskCB(shellEntryId);
+    return !OsTaskIsUnused(taskCB) &&
+           (strlen(taskCB->taskName) == SHELL_ENTRY_NAME_LEN &&
+            strncmp(taskCB->taskName, SHELL_ENTRY_NAME, SHELL_ENTRY_NAME_LEN) == 0);
+}
+
 INT32 ConsoleTaskReg(INT32 consoleID, UINT32 taskID)
 {
-    if (g_console[consoleID - 1]->shellEntryId == SHELL_ENTRYID_INVALID) {
+    UINT32 intSave;
+
+    LOS_SpinLockSave(&g_consoleSpin, &intSave);
+    if (!IsShellEntryRunning(g_console[consoleID - 1]->shellEntryId)) {
         g_console[consoleID - 1]->shellEntryId = taskID;
+        LOS_SpinUnlockRestore(&g_consoleSpin, intSave);
         (VOID)OsSetCurrProcessGroupID(OsGetUserInitProcessID());
         return LOS_OK;
     }
-
-    return LOS_NOK;
+    LOS_SpinUnlockRestore(&g_consoleSpin, intSave);
+    return g_console[consoleID - 1]->shellEntryId == taskID ? LOS_OK : LOS_NOK;
 }
 
 BOOL SetSerialNonBlock(const CONSOLE_CB *consoleCB)
diff --git a/net/lwip-2.1/enhancement/src/api_shell.c b/net/lwip-2.1/enhancement/src/api_shell.c
index 28921cd4..b6330d3e 100644
--- a/net/lwip-2.1/enhancement/src/api_shell.c
+++ b/net/lwip-2.1/enhancement/src/api_shell.c
@@ -1568,7 +1568,7 @@ static void lwip_ping_usage(void)
            "\n  ping [-n cnt] [-w interval] [-l data_len] destination"
            "\n  ping [-t] [-w interval] destination"
            "\n  ping -k");
-    PRINTK("\n  -t means ping forever, user can use -k to stop the forever ping");
+    PRINTK("\n  -t means ping forever, user can use -k to stop the forever ping\n");
 }
 
 LWIP_STATIC int osPingFunc(u32_t destip, u32_t cnt, u32_t interval, u32_t data_len)
diff --git a/shell/full/src/cmds/shell_shellcmd.c b/shell/full/src/cmds/shell_shellcmd.c
index 38124666..989f0713 100644
--- a/shell/full/src/cmds/shell_shellcmd.c
+++ b/shell/full/src/cmds/shell_shellcmd.c
@@ -31,6 +31,10 @@
 
 #include "shcmd.h"
 
+#define DEFAULT_SCREEN_WIDTH 80
+#define MAX_CMD_KEY_WIDTH    12
+#define CMD_ITEM_PER_LINE    (DEFAULT_SCREEN_WIDTH / (MAX_CMD_KEY_WIDTH + 1))
+
 UINT32 OsShellCmdHelp(UINT32 argc, const CHAR **argv)
 {
     UINT32 loop = 0;
@@ -45,15 +49,16 @@ UINT32 OsShellCmdHelp(UINT32 argc, const CHAR **argv)
 
     PRINTK("*******************shell commands:*************************\n");
     LOS_DL_LIST_FOR_EACH_ENTRY(curCmdItem, &(cmdInfo->cmdList.list), CmdItemNode, list) {
-        if ((loop & (8 - 1)) == 0) { /* 8 - 1:just align print */
+        if ((loop % CMD_ITEM_PER_LINE) == 0) { /* just align print */
             PRINTK("\n");
         }
-        PRINTK("%-12s  ", curCmdItem->cmd->cmdKey);
+        PRINTK("%-12s ", curCmdItem->cmd->cmdKey);
 
         loop++;
     }
-
-    PRINTK("\n");
+    PRINTK("\n\nAfter shell prompt \"OHOS # \":\n"
+           "Use `<cmd> [args ...]` to run built-in shell commands listed above.\n"
+           "Use `exec <cmd> [args ...]` or `./<cmd> [args ...]` to run external commands.\n");
     return 0;
 }