In order to sort out the thermal dynamic characteristics and driving factors of rivers in the inland arid region, based on the systematic investigation of the water temperature of Yili River, a numerical model of river hydrodynamic-water temperature based on HEC-RAS was constructed. Remote sensing meteorological spatio-temporal data was used to analyze the variation law of the water temperature of the 210 km section downstream of the reservoir at the outlet of the Yili River. The impacts of the development and utilization of water resources and future climate change on the water temperature of the river were quantified and discussed.The results show that the constructed HEC-RAS model can identify the impacts of the development and utilization of water resources and climate change. In April, the low-temperature water discharged from large reservoirs is limited by the small temperature difference between water and air, and the downstream river warms up slowly along the way, and measures such as stratified water intake have limited effects. The changes in river flow caused by water intake and other behaviors have changed the heat capacity of the river, resulting in differences in the variation law of water temperature. When the river flow decreases in April, the rise in water temperature is not significant, but when the flow increases, the water temperature decreases significantly, with a maximum decrease of -0.60℃. When the flow decreases in July, the rise in water temperature changes significantly, with a maximum increase of 0.65℃, and when the water volume increases, the water temperature changes little.Under different climate models of low, medium and high carbon emission scenarios in the future, the water temperature of the Yili River will show an upward trend on the long time scale from 2020 to 2080. The increase range and fluctuation range of the water temperature are both lower than the air temperature. The average 10-year temperature increase rate at section 2 is 0.09,0.21, and 0.56℃ respectively. It is predicted that by 2080, the increase in water temperature caused by the decrease of river water volume will account for 6% and 21% in April and July, respectively. Keywords: river thermal dynamics; human activities; reanalysis data; climate change; long-term scale; HEC-RAS model; Ili River 〖FL