Abstract: The traditional slope stability analysis method is limited to only single slope body profile of two dimensions, and finally only one safety coefficient is achieved. To overcome this defect, this paper introduces the analysis method of zone safety degree, and with the help of the embedded FISH language of FLAC^3D, the program of zone safety degree calculation is written, the distribution of zone safety degree in this mine is gained taking an open-underground combined mine as example. The results show that, the places with zone safety degree less than 1 are concentrated in the eastern and south sides of slope, and the smallest zone safety degree 0.91 appeared in the southern slope, which provides scientific guidance to the safe production of the mine and full recovery of the ore.