A method performed by a first terminal performing vehicle-to-everything (V2X) communication with a second terminal via one or more PC5 unicast links in a wireless communication system is provided. The method may include: receiving, from a core network entity, information on one or more security policies respectively corresponding to the one or more PC5 unicast links, wherein each of the one or more PC5 unicast links is associated with one or more V2X services; transmitting, to the second terminal, a direct communication request message including the one or more security policies for initiating the V2X communication; and in case that the transmitted direct communication request message is accepted by the second terminal, activating a security of each of the one or more PC5 unicast links based on the received information on the one or more security policies.