Abstract: Anjialing Open-pit Mine gradually formed a unique open-underground combined mining mode.The north slope of Anjialing Open-pit formed double effect of underground mining and fault fracture zone in 2^# Mine, which took threat for open pit safe and orderly production. With the advancing of 29211 working face in 2^# Mine, the north slope Anjialing Open-pit appears deformation, Morgenstern-price method is adopted for slope stability evaluation. When working face advance to design stop mining line, slope safety coefficient is insufficient, existing risk of geological disasters, in combination with the slope stability of radar and GPS monitoring data analysis, the 29211 working face in 2^# Mine regulates the original design of stop line position, which ensures the safety in open pit mining.