The spatial-temporal variation of total dissolved solids (TDS) in Bosten Lake and it's driving factors after the implementation of the Kaiduhe River-the Huangshuigou River-the Great Lake-the Small Lake connectivity project were analyzed in order to provide practical guidance for the improvement of water environment in Bosten Lake. The results show that in terms of spatial variation, the connectivity project of the Bosten Lake water system promoted the water circulation in the Great Lake and the Small Lake area, alleviated the TDS in Bosten Lake with the decrease of 0.5-1.0 g/L TDS in the Huangshuigou River (Nanda Sluice), 0.3-0.5 g/L in the northwestern and southeastern part of the Great Lake, and 0-1.5 g/L in the eastern part of the Small Lake. In terms of time variation, the changes of TDS content in the Huangshuigou area, the west Coast area, the Great Lake and the Small Lake of Bosten Lake were highly synchronized. The implementation of the water system connectivity project had a significant effect on improving the spatial distribution of TDS in Bosten Lake. The diffusion of water with higher TDS, water level, especially water temperature all contributed to the temporal changes of TDS. With the implementation of the water system connectivity project, it is crucial to regulate the inflow and outflow of the lake reasonably in a year, and strictly prevent sewage from entering the rivers and lakes.