According to one embodiment of the present specification, a method for transmitting a trigger frame for requesting uplink data to be received through an wireless resource individually configured in an overlapped time duration from a plurality of terminals in a wireless LAN system, comprises: a step for receiving, by an access point, a first buffer state frame from a first terminal, wherein the first buffer state frame includes first QoS information of first uplink data; a step for receiving, by the access point, a second buffer state frame from a second terminal, wherein the second buffer state frame includes second QoS information of second uplink data; a step for determining, by the access point, a first primary AC for a trigger frame on the basis of the first QoS information and the second QoS information, wherein the access point includes a plurality of AP buffers for downlink data to be transmitted to a plurality of terminals; and a step for transmitting, by the access point, the trigger frame through the downlink buffer corresponding to the determined first primary AC among the plurality of AP buffers.