As an early American statesman and a founding father, Hamilton attaches great importance to analyzing the relationship between human psychology and political activities, and emphasizes that the science of policymaking lies in the cognition of human nature. Hamilton’s view of human nature is neither the idealistic theory of good nature nor the pessimistic theory of evil nature, but an ideological system of human nature with rich connotation and internal tension, which combines classical, Christian and enlightenment human nature thoughts, and contains complex understanding of human nature, psychological motivation and behavioral principles. It is not difficult to find that Hamilton’s thought of human nature actually provides the essential cognitive motivation of human nature for his political philosophy, whether it is the theory of human nature motive embodied in the regime structure of separation of powers and checks and balances, or the idea of natural nobility contained in the representative republic system.