A method and an apparatus for terminating a cellular network connection of a terminal that is connected without authentication are provided. The disclosure relates to a communication technique and a system for fusing a 4th generation (4G) system and a 5th generation (5G) communication system to support higher data rates, which is subsequent to the 4G system, with Internet-of-things (IoT) technology. The disclosure may be applied to intelligent services (e.g., smart home, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail business, security and safe-related services, or the like) based on 5G communication technology and IoT-related technology.