为研究泥岩边坡在库水位骤降与不同降雨类型耦合情况下的渗流特性和稳定性规律，基于岩体非饱和理论和Hoek-Brown准则，利用极限平衡理论推导出库水位与降雨耦合情况下的边坡稳定系数表达式，并利用Geo-slope软件对泥岩边坡进行数值模拟。结果表明：（1）库水位骤降情况下，孔压先减小后保持不变，监测点距库岸越远，孔压的变化幅度越小，边坡稳定系数随时间变化呈现先减小后增大，之后保持不变的规律，库水位下降速率越大，最小稳定系数越小，且其出现的时间越早；（2）不同静库水位耦合不同类型降雨情况下，孔压先增大后减小，静库水位越高，整体孔压越大；（3）库水位骤降偶遇降雨边坡内部的孔压逐渐减小，在降雨过程中陡然上升，当平均型降雨发生在库水位骤降第24~26 d时，最小稳定系数达到最小。该研究成果为正确认识降雨耦合库水位骤降情况下的岩质边坡稳定性规律提供了参考。

In order to study the seepage characteristics and stability law of mudstone slope under the coupling of sudden drop of reservoir water level and different rainfall types，based on the unsaturated rock mass theory and Hoek-Brown criterion，the expression of slope stability coefficient under the coupling of reservoir water level and rainfall was derived by using limit equilibrium theory，and numerical simulation of mudstone slope was carried out by using Geo-slope software.The results show that the pore pressure decreases first and then remains unchanged when the reservoir water level drops suddenly.The farther the monitoring point is from the reservoir bank，the smaller the variation amplitude of pore pressure is.The slope stability coefficient decreases first and then increases with time，and then remains unchanged.The larger the reservoir water level dropping rate is，the smaller the minimum stability coefficient is and the earlier it occurs.The pore pressure increases first and then decreases under the condition of different static reservoir water level coupling different types of rainfall.The higher the static reservoir water level is，the larger the overall pore pressure is.When the reservoir water level drops suddenly and encounters occasional rainfall，the overall trend of pore pressure in slope decreases gradually and rises abruptly in the process of rainfall.The minimum stability coefficient is the smallest when the mean rainfall occurs at the 24~26 d of the sudden drop of the reservoir water level.The research results provide a reference for correctly understanding stability law of rock slope under the condition of sudden drop of reservoir water level coupled with rainfall.