Disclosed are a method and apparatus for beam training phase automatic gain control. Said beam training phase automatic gain control method comprises: a sending device sequentially using a send beam to send an AGC training sequence to a receiving device, and the receiving device sequentially using a receive beam to receive a corresponding AGC training sequence; the receiving device executing an AGC algorithm after each time the device receives an AGC training sequence, acquiring the AGC gain control value αi corresponding to the current send and receive beam combination, where 1≤i≤n; when a supported beam training strategy is beam training based on channel estimation, the receiving device, after acquiring a number n of AGC gain control values αi corresponding to send and receive beam combinations, selecting a single αi as a uniform optimal AGC gain control value α̂, sequentially receiving a beam training pilot sent by the sending device, and using the uniform optimal AGC gain control value α̂ to perform automatic gain control on each beam training pilot received.