the invention involves a method and a system for station switching when a wireless terminal point completes wireless local area network privacy infrastructure in a convergent wlan . the method includes steps as follows . the sta implements re - association rebinding process with a target access controller over a target wtp . a base key is requested by the target ac from an associated ac . an associated wtp is informed to delete the sta by the associated ac , and the target wtp is informed to add the sta by the target ac . a session key is negotiated based on the requested base key by the sta and the target ac , and is synchronized between the target ac and the target wtp . the method enables fast and safe switching of the sta between wtps under the control of different controllers in the convergent wlan based on wapi protocol .