[Objective] The monitoring and evaluation of the ecological effect of soil and water conservation in the open-pit coal mine project were conducted in order to determine the protection effect and the feasibility of the soil and water conservation measures.[Methods] With the actual monitoring data, we took Xiwan open-pit coal mine in Shaanxi Province and coal preparation plant project as an example in this study. The evaluation index system was established in terms of soil and water conservation and vegetation recovery. The index weight was determined by Delphy method and the comprehensive evaluation model was established by linear weighted sum method to calculate the value of ecological effect of soil and water conservation in different periods of the project construction.[Results] The results showed that the value of ecological effect of operation period (0.683) > trial operation period (0.344) > early construction period (0.213). Since the implementation of the project, the total area of soil and water erosion has decreased from 426.71 hm² to 376.63 hm², the vegetation coverage has increased from 20.20% to 27.18%, the interception runoff has increased by 7 530 m³, and the soil conservation has increased by 6.90×10⁴ t.[Conclusion] Xiwan open-pit coal mine in Shenyu Mining area of Shaanxi Province has got good control effect and ecological effect by implementing soil and water conservation engineering and plant protection system designed by soil and water conservation scheme.