This application provides a session management method and an apparatus. The session management method includes: A terminal device determines a first parameter, where the first parameter is used by a first network device to determine first inactivity duration of a first quality of service QoS flow of the terminal device, or is used by the first network device to determine first inactivity duration of a first session of the terminal device. The terminal device sends a first message to the first network device, where the first message includes the first parameter.