The present invention discloses as synchronization method of a layered wireless access system, which is applied to the layered wireless access system including an access point management unit located in an access layer and its linked access points. The access point management unit has a timing server, each access point having a timing client. The timing server generates timing information and distributes it to the timing client of each linked access point, and the timing client recovers the timing information as a local timing reference signal. The method may implement clock synchronization between the access point management unit and the access points to ensure the normal operation of the system. The present invention also provides network management, scheduling, frequency assignment and flow control methods based on the layered wireless access system.