Abstract: It is always difficult to solve the problem of the searching method for the critical slip surface of high-steep slopes under loads in geotechnical engineering. The critical slip surface is controlled by two aspects, one is the combination relation with rock mass discontinuity and slope, and the other is the size and the location the loads. The shape and position of 3-D critical slip surface of high-steep slope intact rock under loads are analyzed based on the stress effect coefficient. The effects of influence factors on the shape and position of 3-D critical slip surface are further analyzed, and the variation of the critical slip line of high-steep slope intact rock under loads is summarized. The range of 3-D critical slip surface of high-steep slopes is determined.