How to Delete all cloudflare records at once

Create a file named cf.sh in your Linux server

#!/bin/bash

TOKEN="xxxxxxxxxxxxxxxxxxx"
ZONE_ID=2222222222222222222222222

# EMAIL=me@gmail.com
# KEY=11111111111111111111111111
# Replace with 
#     -H "X-Auth-Email: ${EMAIL}" \
#     -H "X-Auth-Key: ${KEY}" \
# for old API keys
 

curl -s -X GET https://api.cloudflare.com/client/v4/zones/${ZONE_ID}/dns_records?per_page=500 \
    -H "Authorization: Bearer ${TOKEN}" \
    -H "Content-Type: application/json" | jq .result[].id |  tr -d '"' | (
  while read id; do
    curl -s -X DELETE https://api.cloudflare.com/client/v4/zones/${ZONE_ID}/dns_records/${id} \
      -H "Authorization: Bearer ${TOKEN}" \
      -H "Content-Type: application/json"
  done
  )


edit TOKEN and ZONE ID 
you can create token from cloudflare > account > api tokens
zone id can be found from domain overview
once file is created 
run

bash cf.sh
and its done