The present disclosure discloses a method for achieving backward compatibility in a large bandwidth wireless network and an Access Point (AP) for solving the technical problem of compatibility between a more effective channelization solution and a plurality of existing channelization solutions. The technical solution of the disclosure is implemented on the basis of time division multiplexing and frequency division multiplexing, and under the time division multiplexing mode, the AP sends/receives wireless frames on channels belonging to a first and a second channelization set respectively and alternately in terms of time according to a communication protocol; and under the frequency division multiplexing mode, the AP independently configures time window parameters and the corresponding main and/or secondary channel parameters on the channels which belong to the first and second channelization sets and are non-overlapped in the frequency domain, and sends/receives the wireless frames. By way of the above solution of the disclosure, the wireless station can establish a large bandwidth wireless network supporting backward compatibility.