Abstract: Based on the principle of global critical slip field, this paper applies four evaluation methods of Ordinary, Bishop, Janbu and Morgenstern-price to establish a global and refined evaluation system for slope stability. The evaluation system was applied to the comprehensive evaluation of the slope stability before and after the presser foot discharge in the West Open-pit Mine. After a comprehensive comparison, the most unstable slope of the West Open-pit Mine was determined, and the backfill presser foot technology was used for treatment and then evaluated again. The evaluation results show that the implementation of the backfill presser foot has greatly and effectively controlled the slope deformation and increased its stability coefficient by 1.4 times. According to the actual monitoring data of the West Open-pit Mine, the evaluation results are safe and reliable and are in good agreement with the actual situation. Compared with a single evaluation method, this evaluation system can consider the uncertainty of many factors in the evaluation of slope stability. By comparing the four evaluation methods, the most reasonable and most suitable method for actual engineering needs is selected to improve the slope stability.