Embodiments of the present invention relate to a communication method and a device in a time division duplexing system. The communication method in a time division duplexing system includes: notifying a user equipment of an uplink-downlink configuration of a radio frame; specifying a part of downlink subframes corresponding to the uplink-downlink configuration of the radio frame as MBSFN subframes; and sending first information to the user equipment, where the first information is used to indicate that multicast areas of the MBSFN subframes are used for uplink communication or downlink communication.