An embodiment of the present invention relates to a method for transmitting or receiving a signal related to mission critical push to talk (MCPTT) of a first device in a wireless communication system, the method comprising the steps of: transmitting a floor request by the first device; receiving a floor request status from a second device having received the floor request; receiving a floor grant from the second device after receiving the floor request status; and transmitting position information of the first device after receiving the floor grant, wherein the first device transmits the position information of the first device together with the floor request when transmitting the floor request.