diff --git a/cmd/completion.go b/cmd/completion.go
deleted file mode 100644
index 9896a5f2d0..0000000000
--- a/cmd/completion.go
+++ /dev/null
@@ -1,195 +0,0 @@
-// Copyright 2020 PingCAP, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package cmd
-
-import (
-	"bytes"
-	"io"
-	"os"
-	"path"
-
-	"github.com/pingcap/errors"
-	"github.com/spf13/cobra"
-)
-
-func newCompletionCmd() *cobra.Command {
-	cmd := &cobra.Command{
-		Use:   "completion SHELL",
-		Short: "Output shell completion code for the specified shell (bash or zsh)",
-		Example: `  # Installing bash completion on macOS using homebrew
-  ## If running Bash 3.2 included with macOS
-  brew install bash-completion
-  ## or, if running Bash 4.1+
-  brew install bash-completion@2
-
-  # Installing bash completion on Linux
-  ## If bash-completion is not installed on Linux, please install the 'bash-completion' package
-  ## via your distribution's package manager.
-  ## Load the tiup completion code for bash into the current shell
-  source <(tiup completion bash)
-  ## Write bash completion code to a file and source if from .bash_profile
-  tiup completion bash > ~/.tiup.completion.bash
-  printf "
-  # tiup shell completion
-  source '$HOME/.tiup.completion.bash'
-  " >> $HOME/.bash_profile
-  source $HOME/.bash_profile
-
-  # Load the tiup completion code for zsh[1] into the current shell
-  source <(tiup completion zsh)
-  # Set the tiup completion code for zsh[1] to autoload on startup
-  tiup completion zsh > "${fpath[1]}/_tiup"`,
-		SilenceUsage:  true,
-		SilenceErrors: true,
-		RunE: func(cmd *cobra.Command, args []string) error {
-			teleCommand = cmd.CommandPath()
-			shell := os.Getenv("SHELL")
-			if len(args) == 1 {
-				shell = args[0]
-			}
-			shell = path.Base(shell)
-			switch shell {
-			case "bash":
-				return cmd.Parent().GenBashCompletion(os.Stdout)
-			case "zsh":
-				return genCompletionZsh(os.Stdout, cmd.Parent())
-			default:
-				return errors.New("unsupported shell type " + shell)
-			}
-		},
-	}
-
-	return cmd
-}
-
-// Followed the trick https://github.com/kubernetes/kubectl/blob/master/pkg/cmd/completion/completion.go#L145.
-func genCompletionZsh(out io.Writer, tiup *cobra.Command) error {
-	zshHead := "#compdef tiup\n"
-	_, _ = out.Write([]byte(zshHead))
-
-	zshInitialization := `
-__tiup_bash_source() {
-	alias shopt=':'
-	emulate -L sh
-	setopt kshglob noshglob braceexpand
-
-	source "$@"
-}
-
-__tiup_type() {
-	# -t is not supported by zsh
-	if [ "$1" == "-t" ]; then
-		shift
-
-		# fake Bash 4 to disable "complete -o nospace". Instead
-		# "compopt +-o nospace" is used in the code to toggle trailing
-		# spaces. We don't support that, but leave trailing spaces on
-		# all the time
-		if [ "$1" = "__tiup_compopt" ]; then
-			echo builtin
-			return 0
-		fi
-	fi
-	type "$@"
-}
-
-__tiup_compgen() {
-	local completions w
-	completions=( $(compgen "$@") ) || return $?
-
-	# filter by given word as prefix
-	while [[ "$1" = -* && "$1" != -- ]]; do
-		shift
-		shift
-	done
-	if [[ "$1" == -- ]]; then
-		shift
-	fi
-	for w in "${completions[@]}"; do
-		if [[ "${w}" = "$1"* ]]; then
-			echo "${w}"
-		fi
-	done
-}
-
-__tiup_compopt() {
-	true # don't do anything. Not supported by bashcompinit in zsh
-}
-
-__tiup_ltrim_colon_completions()
-{
-	if [[ "$1" == *:* && "$COMP_WORDBREAKS" == *:* ]]; then
-		# Remove colon-word prefix from COMPREPLY items
-		local colon_word=${1%${1##*:}}
-		local i=${#COMPREPLY[*]}
-		while [[ $((--i)) -ge 0 ]]; do
-			COMPREPLY[$i]=${COMPREPLY[$i]#"$colon_word"}
-		done
-	fi
-}
-
-__tiup_get_comp_words_by_ref() {
-	cur="${COMP_WORDS[COMP_CWORD]}"
-	prev="${COMP_WORDS[${COMP_CWORD}-1]}"
-	words=("${COMP_WORDS[@]}")
-	cword=("${COMP_CWORD[@]}")
-}
-
-__tiup_filedir() {
-	# Don't need to do anything here.
-	# Otherwise we will get trailing space without "compopt -o nospace"
-	true
-}
-
-autoload -U +X bashcompinit && bashcompinit
-
-# use word boundary patterns for BSD or GNU sed
-LWORD='[[:<:]]'
-RWORD='[[:>:]]'
-if sed --help 2>&1 | grep -q 'GNU\|BusyBox'; then
-	LWORD='\<'
-	RWORD='\>'
-fi
-
-__tiup_convert_bash_to_zsh() {
-	sed \
-	-e 's/declare -F/whence -w/' \
-	-e 's/_get_comp_words_by_ref "\$@"/_get_comp_words_by_ref "\$*"/' \
-	-e 's/local \([a-zA-Z0-9_]*\)=/local \1; \1=/' \
-	-e 's/flags+=("\(--.*\)=")/flags+=("\1"); two_word_flags+=("\1")/' \
-	-e 's/must_have_one_flag+=("\(--.*\)=")/must_have_one_flag+=("\1")/' \
-	-e "s/${LWORD}_filedir${RWORD}/__tiup_filedir/g" \
-	-e "s/${LWORD}_get_comp_words_by_ref${RWORD}/__tiup_get_comp_words_by_ref/g" \
-	-e "s/${LWORD}__ltrim_colon_completions${RWORD}/__tiup_ltrim_colon_completions/g" \
-	-e "s/${LWORD}compgen${RWORD}/__tiup_compgen/g" \
-	-e "s/${LWORD}compopt${RWORD}/__tiup_compopt/g" \
-	-e "s/${LWORD}declare${RWORD}/builtin declare/g" \
-	-e "s/\\\$(type${RWORD}/\$(__tiup_type/g" \
-	<<'BASH_COMPLETION_EOF'
-`
-	_, _ = out.Write([]byte(zshInitialization))
-
-	buf := new(bytes.Buffer)
-	_ = tiup.GenBashCompletion(buf)
-	_, _ = out.Write(buf.Bytes())
-
-	zshTail := `
-BASH_COMPLETION_EOF
-}
-
-__tiup_bash_source <(__tiup_convert_bash_to_zsh)
-`
-	_, _ = out.Write([]byte(zshTail))
-	return nil
-}
diff --git a/cmd/root.go b/cmd/root.go
index 0a522821ad..a8cc188cab 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -163,7 +163,6 @@ the latest stable version will be downloaded from the repository.`,
 		newCleanCmd(),
 		newMirrorCmd(),
 		newTelemetryCmd(),
-		newCompletionCmd(),
 		newEnvCmd(),
 	)