The change in water level in front of the slope causes changes in seepage flow inside the slope, resulting in a significant mutual influence between the seepage field and stress field inside the slope. At present, the research on the change of stress field and deformation field in slope caused by water level drop is not perfect. The traditional calculation method is still mainly used for stress-deformation analysis and stability calculation of slope under corresponding working conditions, and only the pore water pressure generated by seepage is considered, but the excess pore water pressure is not considered, which directly affects the accuracy of calculation results. In order to better study the changes in slope stability and factors affecting slope stability under water level drop conditions, this article considers the fluid structure coupling effect and conducts research on the changes in seepage field and stress field inside the slope under water level drop conditions.