One embodiment of the present invention provides a method and device for performing a device-to-device (D2D) service in a wireless communication system and, more particularly, provides a method performed by a group leader device supporting the D2D service in a wireless communication system comprising a seller device and a customer device which support the D2D service. The group leader device forms a D2D terminal group including a plurality of customer devices. Information on the D2D terminal group is provided to the seller device so as to enable a reasonable transaction between the seller and a customer to be carried out.