As a focus of landscape ecology, ecological security pattern is of great significance for maintaining the level of regionally ecological security and realizing regional sustainable development. Selecting the Pudacuo National Park in Yunnan Province as the research area, this paper uses InVEST model to assess the temporal and spatial evolution of its habitat quality based on three phases of land use data in 2000, 2010 and 2017, which paves the way for the determination of the ecological source. Five relevant resistance factors, including slope, land use type, habitat quality index, vegetation coverage (indicated by NDVI), and distance from the water area, are selected to establish resistance surface, as well as the resistance threshold method is used to extract key protection areas. Finally, the minimum cumulative resistance model is used to establish ecological corridors and ecological strategic nodes for constructing the ecological security pattern of Pudacuo National Park. The results show that: (1) there are wide discrepancies among the spatial distribution of habitat quality in Pudacuo National Park, which is related to land use types. The overall habitat quality is at a high level with high habitats accounting for more than 80.0%. (2) From 2000 to 2017, the average habitat quality of the study area firstly declined and then remained basically unchanged for 0.8392, 0.8295 and 0.8294, maintaining a relatively high level overall, with the average habitat quality being above 0.8. The area percentage increases with the change in habitat quality accordingly. (3) The distribution of ecological sources in the researched study area is relatively concentrated on the whole, accounting for 2.3% of the total area of Pudacuo National Park. The distribution of the minimum cumulative resistance value is generally variant. (4) The ecological corridor presents a ring-shaped pattern. The ecological strategic nodes are located in the center of the ring and the upper area of the ring while the protection key area shows a ″double triangle″ shape. The results are conducive to presenting the temporal and spatial evolution process of the habitat quality of Pudacuo National Park, which has positive guiding significance for the reasonable and sustainable use and development of land resources, and provides reference for the ecological protection of the national parks in our country.In addition, this paper has the following four innovations: 1. Try to carry out habitat quality assessment and ecological security pattern construction of China's emerging entity National Park. 2. In terms of research methods, we try to use the results of habitat quality assessment in the early stage as the basis for the construction of ecological security pattern in the later stage. 3. Select the typical Pudacuo National Park to construct the habitat quality and ecological security pattern, and provide reference for the ecological environment protection of other national parks in China. 4. Based on invest model and MCR model, the habitat quality and ecological security pattern of Pudacuo National Park were studied.