Value is the essence of human self-development in discovery, creation and innovation. Value comes from nature and develops with the evolution of human beings and the development of society. The ultimate origin of value can only be the moving material world and the working human society. Value includes the dual development of human consciousness and life, and the unified development of human and external nature. All the development of the world created by human self is valuable, and the core essence of value is free man. A man who creates his own existence is a free man. Man himself is the fundamental object of value, man is the ontology of value, man's behavior is the source of value, and man's development is the result of value. Human development is the unified development of human internal contradictions and external contradictions, the all-round development of human consciousness and life, and the all-round development of human and nature. That is, the unity of man's internal self-creation and external creation with nature, and this kind of free creation is still a valuable act, then the overall value is the realization of freedom.