Abstract: [Objective]To explore the response law of dynamic water pressure landslides to rainfall, [Methods]taking the Bazimen landslide in the Three Gorges Reservoir area as an example, combined with geological survey data, correlation analysis, and finite element numerical simulation, the influence of rainfall on landslide deformation was systematically studied, revealing its response law and deformation mechanism. [Conclusion]Research has shown that fluctuations in reservoir water and rainfall are the main driving factors for the deformation of the Bazimen landslide. The impact of rainfall on landslide deformation is manifested as follows: during the stage of reservoir water decline, rainfall replenishes the internal water head of the slope, further enhancing the effect of dynamic water pressure and significantly exacerbating slope deformation; During the rising stage of reservoir water, rainfall infiltrates to the rear edge of the secondary sliding zone, causing an increase in pore water pressure, which in turn triggers deformation of the landslide rear edge and drives overall deformation of the landslide. Adequate rainfall is the main triggering factor for landslide deformation during the rising stage of reservoir water. The deformation of landslides exhibits a certain lag, with a lag time of about 20 days for deformation caused by a decrease in reservoir water and 9 days for deformation caused by rainfall. The attenuation degree of landslide stability coefficient (1.029) under the condition of long-term continuous rainfall is higher than that under the condition of rainstorm (1.039). The research results have deepened the understanding of the deformation mechanism of dynamic water pressure landslides and can provide reference for the early warning and prediction of such landslides.