Disclosed are an uplink and downlink transmission resource allocation method and device. In this application, a first channel is transmitted on a specified time-frequency resource within a first channel transmitting period according to the first channel transmitting period. The first channel is at least used for notifying allocation information of an uplink transmission resource and a downlink transmission resource within the first channel transmitting period or an effective time period of the first channel, so that dynamic partitioning and notification of the uplink transmission resource and the downlink transmission resource are achieved.