A wake-up signal detection method and an apparatus are provided, and are applicable to fields such as V2X, the internet of vehicles, an intelligent and connected vehicle, assisted driving, and intelligent driving. The method includes: determining, by a terminal device, N PDCCH monitoring occasions before an active time DRX ON; and detecting a wake-up signal WUS on M of the N PDCCH monitoring occasions, where M is less than N, and both N and M are positive integers greater than 1. The wake-up signal WUS is detected by using the method, so that power consumption of the terminal device can be effectively reduced, and a power saving gain can be improved.