The present invention provides a method for accessing a wireless network, so as to implement acquisition of system synchronization during the process of accessing the wireless network in the situation that a physical frame structure can be configured dynamically. The method for acquiring system synchronization comprises: searching a physical frame on a current sub-channel; resolving a system information channel (SICH) and a control channel (CCH) in the found physical frame, wherein the SICH indicates a structure of the physical frame, and the CCH indicates allocation of system resources; and acquiring a system parameter from the physical frame by using the resolving result. A device for implementing the above method is further provided.