The invention provides a community access control door opening method and system based on a WeChat platform, and belongs to the technical field of access control, the system comprises a terminal device, a WeChat server, an access controller and an access control terminal, the terminal device comprises a management end, an owner end and a visitor end, the WeChat server is in communication connection with the terminal device and the access controller, and the access control terminal is in communication connection with the terminal device and the access controller. The entrance guard terminal comprises a gate entrance guard terminal and a building entrance guard terminal, the entrance guard terminals are electrically connected with the entrance guard controller, visitors visit WeChat official accounts and register visitor names, visiting reasons and visited person information, the WeChat server pushes visitor information to WeChat of corresponding owners, the owners judge whether the visitors are safe visitors according to the visitor information, and if the visitors are safe visitors, the entrance guard terminals are connected with the entrance guard controller. The WeChat server generates a temporary two-dimensional code picture and pushes the temporary two-dimensional code picture to the WeChat of a safe visitor, the visitor aligns the temporary two-dimensional code picture to the two-dimensional code recognition modules on the gate access control terminal and the building access control terminal, and after the recognition is successful, the access controller outputs a control instruction to control the access control to be opened.