The invention relates to a 5G downlink channel signal diversity reception method, and belongs to the field of mobile communication. The method comprises: S1, a terminal starting receiving modes of allantenna arrays, and calculating the receiving signal intensity of the antenna arrays; S2, selecting a main antenna array, and determining the incoming wave direction of the base station; S3, the terminal diversity receiving different antenna arrays, and generating a corresponding receiving shaping matrix according to a physical downlink signal incoming wave azimuth angle; and S4, the terminal side receiving the physical channel data by using different antenna array diversity, performing diversity combining processing by using a maximum ratio combining algorithm, and calculating to obtain a terminal diversity receiving result. According to the method, the receiving gain of the physical downlink signal of the terminal is improved, the characteristics of poor millimeter wave spatial propagation and strong directivity can be effectively resisted, and the millimeter wave receiving performance of the terminal is improved.