Disclosed are a traffic transmission method and device, the method being performed by a terminal in a wireless communication system. Specifically, a non-access point (AP) STA of the present invention can receive, from an AP, a trigger frame triggering the transmission of a physical layer protocol data unit (PPDU). The trigger frame includes information indicating at least one traffic identifier (TID) that is allowed to be transmitted in a target wake time (TWT) period. The TWT period may indicate a period in which the transmission of traffic for the at least one TID having a specific transmission condition is allowed, and the transmission of traffic not having the specific transmission condition is restricted. Thereafter, the non-AP STA transmits a PPDU, including the traffic corresponding to the at least one TID, to the AP within the TWT period.