Abstract: Using the Moon Mountain Nature Reserve in Guizhou as a case study, this research analyzes changes in habitat quality through the application of the propensity score matching model and the InVEST model. The analysis utilizes land use data from the reserve and its surrounding 15 km area for the years 2000, 2010, and 2020 to evaluate the spillover effects of the reserve. The findings indicate that land type transitions within the entire study area over the past two decades primarily involved farmland and shrubs. Specifically, farmland increased by 11.94 km² within the protected area, while adjacent regions saw an increase of 75.68 km²; nevertheless, forest remained the predominant land type. Moreover, the average habitat quality across the entire study area experienced a significant decline over the last two decades, with the rate of habitat quality change increasing from the reserve outward. The Moon Mountain Nature Reserve exhibited a leakage effect, negatively impacting the habitat quality in the surrounding 0-10 km area. Furthermore, variations in population density, GDP, and elevation were found to have a substantial influence on habitat quality changes both within and around the reserve, suggesting that human activities may intensify the pressures on the protected area. This study provides a foundation for periodic assessments of the Moon Mountain Nature Reserve and contributes to the enhancement of its management and conservation strategies