Abstract: Most of the failure occurred in the reservoir bank slope is related to the fluctuation of the reservoir water level. In order to effectively guide the slope design and prevent, regard the slope of the upper reservoir area of Shaanxi Zhen'an Pumped-storage Power Station as the object of the research. Using Rocscience Phase2 finite element software, simulate the seepage field-stress coupling field in the slope under drawdown conditions by transient flow and then calculate the stability of the upstream and the downstream slope by the method of SSR search area.It was found that when the water level rose at a constant speed, the safety factor of the downsteam slope continues to decrease with the water level rising, while the safety factor of the upsteam slope decreases first and then increases, but no damage occurs on both sides of the slope. When the water level falls, the downsteam slope safety factor also continued to decrease, but no damage occurred. The safety factor of the upsteam slope also continued to decrease. However, it dropped sharply when the water level dropped by 19m and eventually destroyed. Under the condition that the water fluctuation is constant, when the speed of the lift changes, the safety factor of the downsteam slope remains basically unchanged. When the water level rise speed increases, the safety factor of the upsteam slope gradually increases. When the water level decline speed increases, it gradually decreased. It is suggested that when the reservoir is operating, the decline of the reservoir water should not exceed 18m. In order to meet the demand of power generation and ensure the simulated slope, the normal water level should be lifted by 12m.