Abstract: A wireless local area network system and a wireless network detection and setup method applied thereto are provided. The system includes a base station and at least one wireless device, wherein a first service set identifier is preset in both of the base station and the at least one wireless device. The method includes following steps: the base station and the at least one wireless device use the first service set identifier to enter a first setup mode; in the first setup mode, the base station is automatically connected to the wireless device via at least one connection path and inspects the at least one connection path; the base station and the at least one wireless device end the first setup mode, stop using the first service set identifier, and switch to use a second service set identifier for connection according to an inspection result.