Lake eutrophication has become the focus of research in the field of water resources and a long-term severe challenge facing the field of the water environment. To explore the nutrient status of lakes in arid and semi-arid regions, taking the typical Lake Daihai water as an example, the trophic status assessment model of Lake Daihai water body was established based on the correlation between TSI_SDD and chromaticity angle, according to the Sentinel_2A and Landsat_8 OLI remote sensing data, and the nutrient state of water body at the long time series scale was retrieved, using the remote sensing image data from 1986 to 2020. The results show that:1) According to the results of the accuracy test, the model of trophic status assessment established in this paper has good accuracy (R²=0.74, RMSE=3.66, MAPE=4.84%). 2) The algorithm was applied to time series MSI, TM, ETM+ and OLI images, and the dynamic characteristics of the nutrient status of the Lake Daihai water body from 1986 to 2020 were obtained. The results showed that the water area of Lake Daihai decreased year by year, showing mild eutrophication most of the time. The eutrophication of the water body generally tends to ease from the edge to the center of the lake. The closer to the shore, the more serious the eutrophication is in general. Towards the center of the lake is mainly mesotrophic, and rarely oligotrophic. 3) The trophic status of the Lake Daihai water body was not significant in correlation with climate factors (temperature, wind speed and precipitation), which explain 13% of temporal and spatial variations. Monthly variation in trophic status, showed a significantly strong correlation, with an explanation rate of 93%.