A message acknowledgement method includes: An access point sends a beacon frame, receives an uplink frame sent by a terminal, and sends an acknowledgement frame for the uplink frame, where the acknowledgement frame includes offset time, and the offset time is a difference between a time point when the access point sends the acknowledgement frame and a time point when the access point sends the beacon frame; compares the difference that is obtained through calculation by the terminal and is between the time point when the terminal receives the acknowledgement frame and the time point when the terminal lately receives a beacon frame with the offset time carried in the acknowledgement frame, and if a difference between the two is within a preset error range, determines that the acknowledgement frame received by the terminal is sent by the access point associated with the terminal.