Abstract:[Objective] To explore the dynamic changes in the environmental quality of the Qinghai-Tibet Plateau and provide reference for ensuring the ecological security of the Qinghai-Tibet Plateau, protecting biodiversity and building a strong ecological barrier. [Methods] Based on five periods of land use data in 1985, 1995, 2005, 2015 and 2022, with the help of the InVEST model, we quantitatively assessed the habitat quality status of the Tibetan Plateau in the past four decades and analyzed its spatiotemporal pattern. Finally, we used bivariate spatial autocorrelation Explore the spatial response of habitat quality to climate change and human activities. [Results] (1) In the past four decades, the habitat index of the Qinghai-Tibet Plateau has increased by 0.0529, and the proportion of higher and higher habitat areas has increased by 5.51% in total, the overall habitat quality level has improved but is still at a low level. (2) In the past 40 years, the habitat quality of most areas on the Qinghai-Tibet Plateau has increased by 48.14%, but the overall spatial distribution of habitat levels has not changed much, and each level area has increased in nested levels from outside to inside. (3) In the past four decades, the main types of environmental quality grade transfer in the Qinghai-Tibet Plateau have remained unchanged, but the intensity of grade transformation has continued to increase. (4) In the past four decades, the habitat quality of the Qinghai-Tibet Plateau has a significant spatial correlation with climate change and human activities, the average annual temperature has a significant spatial negative correlation with the habitat quality, the annual precipitation and human activity intensity have a significant spatial correlation with the habitat quality, there is a significant positive spatial correlation. [Conclusion] The research results reveal the spatiotemporal evolution characteristics of the Qinghai-Tibet Plateau's habitat quality, and clarify that climate change and human activities have a profound impact on habitat quality. In the future, bottom-line constraints and human activity guidance should be strengthened.