The invention discloses an access control system based on smart phones and a control method of the access control system. The access control system comprises smart phones, a cloud management server and an access control terminal, wherein the access control terminal and the smart phones are connected with the cloud management server through the Internet. The access control system based on the smart phones and the control method of the access control system have the beneficial effects that hardware-free terminal and unmanned management of the access control system can be achieved by entering and exiting the access control system in a manner of using dynamic access codes by virtue of the smart phones of users, so that the convenience is brought for the users and visitors; different access control permissions are set for different users, the visitors can go in and out in the range of the access control permissions by virtue of the dynamic access codes sent by the users, the visitors are monitored by the GPS (global positioning system) of the access control system, and the dynamic access codes are invalid after being used, so that the safety of the access control system is greatly improved; the access control system is low in cost and wide in range of application, and can be used in places such as banks, hotels, management of parking lots, machine rooms, office rooms, residence communities, factories and the like.