China is currently proposing to build the world’s biggest national park system, but the country’s existing natural conservation is easily affected by population growth and economic pressures. The Huangshan National Park construction area holds great ecological significance and is one of 49 national parks to be established in China. It locates in the Yangtze River Delta region, where the conflict between people and land is intense. Based on this, this paper quantifies the species richness, ecosystem services, and landscape diversity values, counts the index of human activity intensity, calculates the protection advantage and irreplaceability values of each planning unit, and completes the boundary delineation of the Huangshan National Park construction area through the analysis of marginal benefits. Finally, this study delineates the boundary of Huangshan National Park with a 37% protection ratio, which is primarily located in the central and southern regions of the research area, covering an area of approximately 9498.41 km². This study develops a scientific boundary delineation solution for the Huangshan National Park construction area, which provides a reference for the spatial management and control of Huangshan National Park and a theoretical foundation for the boundary delineation of Chinese potential national parks in the future.