This application provides a power adjustment method and apparatus. The method includes obtaining a to-be-output signal, performing first automatic gain control (AGC) processing on the to-be-output signal to obtain the to-be-output signal on which the first AGC processing is performed, and to obtain a gain value of the to-be-output signal. The method also includes performing digital pre-distortion (DPD) processing on the to-be-output signal on which the first AGC processing is performed, to obtain the to-be-output signal on which the DPD processing is performed. The method further includes calculating an output power back-off (OBO) value based on the gain value, adjusting, based on the OBO value, output power of the to-be-output signal on which the DPD processing is performed, and sending, to a signal receive end, the to-be-output signal on which the power adjustment is performed.