The use of full digital coding in millimeter-wave massive MIMO systems requires a large number of radio frequency(RF) chains, resulting in excessive energy consumption. A beam selection scheme based on discrete cuckoo algorithm (DCS) is proposed to reduce the number of required RF chains without obvious performance loss. Firstly, the beam selection model of millimeter wave massive MIMO system is analyzed, and the DCS algorithm is used to solve the model. Owing to the the abnormal coding in the Levy flight discretization result,the heuristic greedy algorithm is proposed to repair it. To speed up the convergence of the algorithm, the replication in the genetic algorithm is introduced into the DCS algorithm, and the global optimal nest is copied to replace the discovered nests. The simulation result shows that the proposed beam selection scheme based on the improved DCS algorithm can obtain better rate performance than several existing schemes.