Abstract: In the practice of leading the Russian revolution and construction, Lenin not only inherited and developed Marxism, but also opened up a new field of Marxist research, and the theoretical exploration and practical application of social psychology were his important theoretical innovations. He insisted on the guidance of historical materialism, and carried on the scientific definition and interpretation of social psychology, not only explained the characteristics of historical materialism of social psychology, but also analyzed its important role. He analyzed and elucidated social psychology theoretically from the three dimensions of macro history, micro life and the dialectical relationship between social existence and social consciousness. At the same time, he also applied theory to practice from the dimensions of mastering the social psychology of the masses, attaching importance to the construction of social psychology, cultivating the class psychology of the proletariat, etc. All these provide beneficial enlightenment for us to pay attention to social psychology from both theoretical and practical aspects in the new era. It includes paying attention to the construction of social psychology, mastering the psychological demands of the people, and using the method of social psychological analysis.