Abstract: In the German Ideology, Marx took the criticism of the abstract narrative of German speculative idealism philosophy as the logical premise, advocating returning the understanding of “human” from the conceptual field to the secular world, placing the “realistic individual” in the specific social and historical process for analysis, treating the realistic individual and their classes as the main subject of political activities, and emphasizing to grasp the essential attributes of “human” from the level of “rough” material production and the social relations it carries. “Realistic individual” was the perceptual force engaged in practical production activities. In the process of practice, “human” externalized and objectified its own essential strength into historical development. Marx pointed out that under the circumstances of the split of capitalist political country and civil society, “human” was alienated into the reality of dual existence, humans in civil society were realistic individuals, but they were not real; The individuals in the political state were real, but they were unrealistic. “Human” under the capitalist social relationship was alienated rational “tool human”. In order to realize the liberation of human personality and free and all-round development, we must get rid of the shackles of idealism and non critical empiricism ideology, engage in the realistic struggle to subvert capitalist private ownership, promote human from human in civil society to socialized human beings, and then truly realize the freedom and development of everyone.