To investigate the evolution characteristics of the water temperature stratification structure in the Xiluodu Reservoir under future climate change, this study proposed a water temperature simulation method coupling the CE-QUAL-W2 model with the LSTM model based on CMIP6 climate scenario data. The LSTM model was used to simulate the reservoir inflow boundary conditions, enabling the CE-QUAL-W2 model to predict water temperature distribution in the Xiluodu Reservoir under different emission scenarios. In addition, the Schmidt stability index (VTG) were introduced to predict and analyze the evolutionary trends of the water temperature stratification structure. The results show that, under different emission scenarios, SSI of the Xiluodu Reservoir exhibits an increasing trend over time, indicating a gradual enhancement of stratification stability, and VTG shows an initial increase followed by a subsequent decrease. Higher emission intensities correspond to greater linear fitting goodness and higher warming rates of surface water temperature, suggesting a more pronounced thermal response of the water body to climate warming. The response intensity to climate change gradually weakens from the surface layer to the bottom layer; however, the long term heat accumulation trend in deep water remains non negligible.