Disclosed in the present invention are a handover method and system for a mobile terminal (MT) based on a wireless local area network. The method includes: sending a data frame to a second AP when an MT needs to hand over from a cell covered by a first AP service to a cell covered by a second AP service, with the data frame including an associated number between the MT and the first AP and an MAC access of the first AP; and the second AP looking up locally stored mobile terminal certification and association information about the cell covered by the first AP service and rapidly determining whether to allow the access of the MT according to the stored information.