In the present study, the urban agglomeration on the northern slope of Tianshan Mountain (UANST) in Xinjiang was taken as the research object. Principal component analysis, coefficient of variation and analytic hierarchy process were used to analyse the indicators based on RS and GIS technology methods. Dimensionality reduction analysis was conducted and the ecological environment quality index (EQI) was calculated, so as to ultimately obtain the spatial distribution characteristics of the ecological environment quality in the area from 2000 to 2018. The use of GIS mapping technology could reflect the changes in the ecological environment of the urban agglomeration over time on the map, dynamic monitoring and quantitative evaluation could be conducted on the ecological environment of the urban agglomeration on the northern slope of the Tianshan Mountains, and the ecological environment over different years could be analysed, including the differences in environmental quality and the reasons for the changes. The results reveal that: in terms of spatial distribution characteristics, the ecological environment quality in Tianshan Mountains had a certain polarization in the spatial distribution; according to the time change pattern, the overall ecological environment quality exhibited a trend of improvement in the past 19 years; in respect of the stability analysis, over 97% of the regional ecological environment quality stability was between weak and medium variation; according to the spatial cluster analysis, the ecological environment quality of the urban agglomeration on the northern slope of the Tianshan Mountains was gathered in high and low values; the coexistence of modes presents a largely “fractured” distribution; and the degree of influence of land use type was relatively high from the perspective of influencing factors. © 2021