[Objective] This study analyzes the accessibility to various types of protected areas and their influencing factors at the national scale, aiming to provide a basis for balancing ecological conservation and development utilization in these areas. [Methods] Based on data from 3464 national-level protected areas in 2021 (national parks, national nature reserves, and national natural parks), this study used the Travel O-D Point Intelligent Query System (TIQS) and Geodetector to investigate the differences in the accessibility to national-level protected areas, their influencing factors, and the spatial relationship between accessibility and population distribution across 2846 county-level administrative divisions. [Results] (1) Accessibility to national parks and national nature reserves showed a pattern of “high in the northwest and low in the southeast”, while national natural parks showed a pattern of “high in the southeast and low in the northwest”. The accessibility to the three types of protected areas formed a spatial complementary pattern. (2) Elevation, terrain relief, and county area were the dominant factors affecting the accessibility to national parks and national nature reserves, while protected area density and elevation were the dominant factors affecting the accessibility to national natural parks. (3) The contradictions and pressures between ecological conservation and human activities faced by the three types of national-level protected areas exhibit significant differences. [Conclusion] There are notable spatial disparities and complementary relationships in accessibility among different types of national-level protected areas. Differentiated conservation and development strategies should be formulated by taking into account multiple factors such as population distribution, resource endowment, and economic development level.