The embodiments of the invention provide a method for establishing a wireless local area network tunnel, an apparatus, and an access network system. An AC sends a first configuration message to an AP, where the first configuration message includes a first tunnel establishment configuration parameter, and the first tunnel establishment configuration parameter includes information about binding between an IP address of at least one BRAS and at least one SSID, so that the AP establishes a data tunnel with the BRAS according to the first tunnel establishment configuration parameter, and the AC establishes a control tunnel with the AP, thereby separating the data tunnel from the control tunnel, and reducing unnecessary overheads of the AC.