This application discloses a precoding processing method and an apparatus. The method includes: A base station determines first downlink channel information based on a pilot signal received from a terminal device. The base station receives a precoding matrix indication PMI from the terminal device, determines second downlink channel information based on the PMI, determines a precoding matrix of a downlink channel based on the first downlink channel information and second downlink channel information, and performs precoding processing by using the precoding matrix. In this method, when calculating a downlink BF weight, the base station combines the downlink channel information obtained based on the pilot signal with the precoding matrix indicated by the PMI, to compensate for a quantization error caused by feedback of a single PMI indication. This method improves accuracy of beamforming weights.