Embodiments of the present invention provide a power usage state information transmission method and apparatus. The transmission method for transmitting power usage state information according to the present invention includes: determining, by a terminal device, a power headroom PH of a second cell corresponding to the terminal device; and sending, by the terminal device to the first network device, the PH and channel configuration information corresponding to the PH. According to the embodiments of the present invention, the first network device can readily acquire, according to the PH and the channel configuration information, a power usage state of the second cell corresponding to the terminal device. In this way, transmit power of UE between different network devices can be properly allocated, and therefore, system resources are properly used.