A method and an apparatus for monitoring a downlink control channel, a terminal device, and a computer readable storage medium. The monitoring method includes determining, by a terminal device, priority information, where the priority information includes at least one of a control resource set priority, a search space priority, a downlink control information priority, or a downlink control information size priority, monitoring, by the terminal device, a downlink control channel based on the priority information, and obtaining, by the terminal device, downlink control information from the downlink control channel.