Embodiments of the present invention provide a power allocation method and a communications device. The power allocation method includes: determining, by a first communications device, a first power control parameter group, where the first power control parameter group includes information used to indicate a transmit power of the first communications device in a first-type subframe, and sending, by the first communications device, a signal only on a downlink frequency resource in the first-type subframe; and determining, by the first communications device, a second power control parameter group, where the second power control parameter group includes information used to indicate a transmit power of the first communications device in a second-type subframe, and sending, by the first communications device, signals on both a downlink frequency resource and an uplink frequency resource in the second-type subframe.