A channel monitoring method and a device are described. The method includes: monitoring, by a terminal device, a first signal on n transmission occasions in a monitoring periodicity; and when the terminal device detects the first signal on at least one of the n transmission occasions, monitoring, by the terminal device, a downlink control channel and/or a second signal in a first time period in the monitoring periodicity; or when the terminal device does not detect the first signal on the n transmission occasions, skipping, by the terminal device, monitoring a downlink control channel in the monitoring periodicity.