Abstract: In The German Ideology, Marx advocated that the understanding of “human” should return to the secular world from the conceptual domain by taking the criticism of the abstract narrative of German speculative idealism philosophy as the logical premise. That is, he believed that “realistic individuals” should be placed in the specific social and historical process for analysis, and the realistic individuals and their classes should be regarded as the main subjects of political activities. He also emphasized that the essential attributes of “human” should be understood from the level of “rough” material production and the social relations it carries. “Realistic individuals” were the perceptual force engaged in actual production activities. In the process of practice, “human” externalized and objectified his own essential strength into historical development. Marx pointed out that under the circumstances of the separation between capitalist political state and civil society, “human” was alienated into the reality of dual existence, in which the humans in civil society were the realistic individuals, but they were not real, and the individuals in the political state were real, but they were unrealistic. “Human” under the capitalist social relationship was alienated rational “tool man”. In order to realize the liberation and free and all-round development of the humans, it is necessary to get rid of the shackles of idealism and non-critical empiricism ideology and to engage in the realistic struggle to subvert capitalist private ownership, so that the humans can be elevated from the “humans” in civil society to the socialized human beings, and then truly realize the freedom and development of everyone.