A downlink channel monitoring method includes monitoring a downlink channel with a first monitoring mode, where the first monitoring mode comprises a full monitoring mode, a wake-up signal monitoring mode, or a sleep signal monitoring mode. Additionally, the method includes monitoring levels of the full monitoring mode, the wake-up signal monitoring mode, and the sleep signal monitoring mode, where the full monitoring mode, the wake-up signal monitoring mode, and the sleep signal monitoring mode are different. Further, the method includes switching, in response to determining that a monitoring situation satisfies a preset condition, a monitoring mode from the first monitoring mode to a second monitoring mode matching the preset condition according to the monitoring levels. Finally, the method includes monitoring the downlink channel with the second monitoring mode, where the second monitoring mode is different from the first monitoring mode.