[Objective] Exploring the ecological and environmental effects and spatial differentiation mechanism of the transformation of production-living-ecological space can provide a scientific basis for coordinating the efficient use of land and the sustainable development of social ecology. [Methods] Taking the upper reaches of the Yangtze River as the research object, the land use transfer matrix and ecological environment quality index were used to quantitatively analyze the spatial differentiation characteristics of production-living-ecological space transfer law and ecological environment effect in the upper reaches of the Yangtze River from 1990 to 2020, and combined with the geographical detector model to identify the driving factors of spatial differentiation of ecological environment quality. [Results] ① The production-living-ecological space pattern in the upper reaches of the Yangtze River is significantly different, and the ecological space is widely distributed in the western and southern regions of the basin. The production space is mainly concentrated in the Chengdu Plain and the intermountain basins scattered in the dense river network and conducive to farming. The living space is scattered in central cities such as Kunming, Chengdu and Chongqing. ② The ecological environment quality is generally stable and dominated by high quality. The spatial pattern of ecological environment quality is low in the middle and high in the surrounding areas. The low quality areas are distributed in lumps and strips in the Sichuan Basin and the north side of the Hengduan Mountains. The medium and high quality areas are mainly distributed in the periphery, southwest and south of the upper reaches of the Yangtze River. ③ The conversion of agricultural production space into forest land production space, water ecological space, and grassland ecological space into forest land ecological space are the main land conversion types that promote the improvement of ecological environment quality. On the contrary, the deterioration of ecological environment quality is closely related to the transformation of forest ecological space into agricultural production space, grassland ecological space and industrial production space. ④ Topographic relief, slope, population density and land use intensity are the main driving factors affecting the spatial differentiation of ecological environment quality. The interaction between natural factors and social factors affects the ecological environment quality in the upper reaches of the Yangtze River. [Conclusion] The ecological quality of the upper reaches of the Yangtze River remains relatively stabilized in general, but the trend of local ecological deterioration should not be ignored, and the land use structure of the production-living-ecological space should be optimized according to the natural conditions of each region, the main function positioning and the actual situation of the ecological environment, etc., in the formulation of future policies.