The invention discloses a method for segmenting flow in wireless local area network. The method comprises the steps that an AP receives network names selected by a WLAN user terminal according to data service, and establishes the mapping relation of the network names and AC addresses according to selected network names; after the WLAN user terminal is connected into access networks, the AP sends the user data sent by the WLAN user terminal to the AC corresponding to the network names of the access networks according to the mapping relation of the network names and the AC addresses. The invention further provides a system for segmenting the flow in the wireless local area network. According to the technical scheme, the problems that data traffic burden on the AC is too large and the data traffic is roundabout in the prior art are solved.