Disclosed are a flexible networking access control method and system, the method comprising: in a region where access control is required, establishing an Ad Hoc network achieving Ad Hoc communication between all areas in the region, the Ad Hoc network comprising cluster heads respectively disposed in all areas to conduct Ad Hoc communication between respective areas, and cluster nodes respectively disposed in all independent functional zones of the all the above areas to conduct Ad Hoc communication with the cluster head in an area; the cluster head in respective areas acquires the user information of a user from the cluster node thereof via the Ad Hoc network, and queries the user information to obtain a user access control authority; according to the obtained user access control authority, the cluster head in respective areas transmits to the cluster node an access control instruction for the cluster node to conduct the access control. The present invention achieves flexible networking and diversified user authority allocation via the Ad Hoc networking mode.