The disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The disclosure provides a method for supporting re-authentication of a PDU session generated through DN authentication/authorization with a DN-AAA server, and a method and an apparatus for managing a corresponding PDU session if DN authorization information is updated at the time of re-authentication.