pip install flask-cors

from flask import Flask, jsonify
from flask_cors import cross_origin

@app.route('/upload', methods=['POST', 'OPTIONS'])
@cross_origin()
def upload():
  # todo
  result_text = {"result": "True"}
  return jsonify(result_text)

from flask import Flask
from flask_cors import CORS

if __name__ == '__main__':
  app.run(host='0.0.0.0', threaded=True, debug=True)
  CORS(app)

@app.after_request
def af_request(resp): 
"""
#请求钩子，在所有的请求发生后执行，加入headers。
:param resp:
:return:
"""
resp = make_response(resp)
resp.headers['Access-Control-Allow-Origin'] = '*'
resp.headers['Access-Control-Allow-Methods'] = 'GET,POST'
resp.headers['Access-Control-Allow-Headers'] = 'x-requested-with,content-type'
return resp