Abstract: Aiming at the problem of mining seepage characteristics of slope with fault under the influence of groundwater.Taking the third mining area of Yimin open-pit mine as the engineering background, the seepage characteristics of groundwater before and after mining and the variation characteristics of seepage field in the process of slope water level dropping are studied by using the method of combining similar model test and numerical simulation.Based on the similar model, the dynamic change process of groundwater level seepage, the law of groundwater level drop after passing through fault, the water position of slope surface and the characteristics of seepage hydraulic gradient in the process of open-pit mine are studied based on the similar model.The change characteristics of slope phreatic line, the law of groundwater jump at fault and the hydraulic gradient characteristics of groundwater under eight different precipitation conditions are studied by numerical simulation.The results show that the groundwater seepage of the slope with faults has jump characteristics; with the increase of seepage time, the seepage affected area gradually extends from the deep to the upper strata of the third mining area; with the drawdown of water level, the hydraulic gradient and the water outlet point of the slope decrease; the hydraulic gradient of groundwater in the similar model is similar to that in the numerical simulation.According to the jump characteristics of groundwater on both sides of the fault, dewatering wells can be set in the geological body between F₁ fault and F₅ fault to realize the control of groundwater level and provide scientific guarantee for drainage and safety production of open-pit mine.