The present invention relates to a wireless communication system, and more particularly, to a service discovery method and device in a wireless LAN system. A service discovery method in a wireless LAN system according to one embodiment of the present invention can comprise: transmitting, by a request device, a service discovery request frame to a response device; and receiving, by the request device, a service discovery response frame, which comprises service information of the response device and service information of each of one or more other devices, from the response device. The one or more other devices can comprise a device which does not belong to the same group as the response device.