Abstract: With Jinxin copper molybdenum mine as engineering background，SURPAC and FLAC^3D are adopted to build the real calculation model of the mine，and the economic data such as the stripping ratio and the quantity of extracted ore are obtained simultaneously.On the premise of keeping safety，three ways of properly increasing the angle and height of single bench，and decreasing the width of cleaning bench can increase the final slope angle of open pit by 2°，drop the stripping ratio from 3.66 to 3.52 and lessen the amount of stripped rocks by 13.5 Mt.All these can efficiently improve the economic benefit of the mine enterprise.Based on this，the stability of the open pit slope after increasing the overall slope angle is analyzed，and its horizontal displacements and failures of the plastic zones are demonstrated.Real-time monitoring on the northern sidewall that is in a high risk is made.The analysis indicated that each new slope is basically in the stable condition and only small part of slope requires local ground support to guarantee the safety in mining.

Key words: Slope design, SURPAC, FLAC^3D, The stripping ratio, Slope stability