The lake water level is an important element of lake hydrological observation, which directly reflects the mass exchange and energy balance of the lake. Moreover, the analysis of lake water level is vital to the study of lake movement and regional climate and environmental change. In order to grasp the change process and spatial characteristics of the water level of inland lakes, both instantaneous and daily mean water level of Xinjiang Bosten Lake were extracted from Jason-1&2, ENVISat&ERS, ICESat-1 and ICESat-2 satellite altimetry data, which were then compared with the water level record of Hydroweb and the measured data of water level and water extent area of Bosten Lake from 1975 to 2020 to ascertain the estimation accuracy of the satellite altimetry data. Furthemore, the trend surface analysis was used to analyze the spatial difference and characteristics of water level change in Bosten Lake. The results showed that the absolute error of the daily mean lake water level of the Hydroweb water level record, Jason-1&2, ENVISat&ERS, ICESat-1, ICESat-2 satellite altimetry data was 0.24, 0.34, 0.28, 0.18 and 0.08 m, respectively. The annual mean water level of Bosten Lake in 2020 reached 1,048.1± 0.12 m, which had an increase of 0.70 ± 0.15 m, compared with that in 1975. The fluctuation of instantaneous water level showed that there was a water level difference on the spatial scale, and ICESat-2 satellite altimetry data accurately described the spatial heterogeneity of lake water surface elevation and change rate of Bosten Lake.