A control information transmission method includes that: a first station sends a wireless signal including control information, where the control information is used for instructing a specified second station in a sleep state to perform one or more of following operations: state update, sleep mode transition, leaving the sleep state, and an operation after leaving the sleep state. A secondary module of the second station receives and decodes a wake-up signal to obtain control information and identity identifier information, and sends the control information and the identity identifier information to a control module; and the control module of the second station determines, according to the identity identifier information, whether the second station is a target second station of the wake-up signal, and parses and completes an operation indicated in the control information.