Abstract: As a key lake in the arid region of Northwest China, Lake Bosten has long been subjected to the dual stresses of salinization and eutrophication, with agricultural and domestic pollution inputs being the core sources of water environment pressure. To improve the lake's ecological conditions, an ecological water conveyance project centered on increasing the inflow of high-quality freshwater into the lake has been implemented in the Huangshuigou since 2018. Based on the water quality monitoring data of Lake Bosten from 2009 to 2024, combined with hydrological data and partial least squares path modeling (PLS-PM), this study systematically analyzed the impact effects and driving mechanisms of ecological water conveyance on the lake's water quality. The results showed that after the implementation of ecological water conveyance, the main water quality indicators in the lake area adjacent to the Huangshuigou (sampling sites 7 and 8) to the lake center (sampling site 15) decreased significantly, with total dissolved solids (TDS) reducing by 32.0%~34.8%, chemical oxygen demand (COD_Cr) by 15.9%~21.6%, total nitrogen (TN) by 19.1%~32.1%, and total phosphorus (TP) by 62.2%~82.3%. Moreover, the concentrations of these indicators gradually stabilized, showing a spatial characteristic of "more significant improvement in nearshore areas and diffusion of benefits to the lake center". Verification by the PLS-PM model indicated that the direct standardized effect of ecological water conveyance on water quality reached 0.870 (P<0.001), making it the dominant driving factor for water quality improvement. This study confirms that the ecological water conveyance in the Huangshuigou is an effective measure to improve the water quality of Lake Bosten, and can provide scientific reference for the precise management and ecological restoration of lakes in arid and semi-arid regions.