Abstract: Promoting the modernization of territory land governance with a high-level spatial planning system has increasingly become a realistic requirement for the comprehensive green transformation of current economic and social development. This paper comprehensively uses the methods of literature research, induction and deduction, and theoretical analysis, systematically combs the ideological origin of spatial planning, compares the international planning practice and exploration, and reveals the evolution of China's spatial planning system. It clarifies the basic theory and connotation of spatial planning system, and then explores the practical direction of its reform based on the new institutionalism theory. The research shows that the connotation of spatial planning presents the evolution trend of "management means - guiding theory - macro system", and the development process of China's spatial planning system forms a pattern of "initial period - development period - transformation period - reconstruction period". Ecological base point, interest midpoint and coordination node are the basis of the connotation and evolution mechanism of the overall spatial planning system. The planning model has initially formed the logical route of "basic theory and practical basis - theoretical framework and planning objectives - spatial classification and zone control - ecological restoration and key construction - planning implementation and supervision - achievements and technical requirements". In the future, the security system of spatial planning should be strengthened in terms of laws and regulations, institutional mechanisms, technological platforms, economic and social services, supervision and management.