The present application relates to a gain control method and an apparatus, comprising an automatic gain controller. An input power of a PSS in an input signal is detected in real time, a rated power of a downlink PSS that acts as a gain control threshold of the automatic gain controller is acquired, and the automatic gain controller is controlled to adjust a value of gain attenuation according to magnitudes of the input power of the PSS and the rated power of the downlink PSS, which is used to adjust an uplink gain and a downlink gain.