Research conclusions: The research results showed that: in natural state，the simulated safety factors of the sliding surface of the 1，2，3and 4 stages were respectively 1． 27，1． 30，1． 56 and 1． 73 and it indicated that the instability would not appear to the four sliding surfaces in a given sliding surface spatial form and in the natural geotechnical parameters conditions． The simulated safety factors of the sliding surface of the 1，2，3and 4 stages were respectively 0． 96，1． 15，1． 48 and 1． 60 when the simulation calculation was made for the geotechnical parameters in the saturation state． If the safety factor fs = 1． 2 was taken as the critical value，it showed in the saturation state，the obvious instability phenomenon appeared to the1 － stage sliding surface，the safety factor of the 2 － stage sliding surface was 1． 15，being at the edge of instability，and the safety factor of the 3 and 4 － stage sliding surfaces was bigger than 1． 2，being in the stable state． These conclusions were basically consistent with the analysis results of the multi － stage landslide in loess area with the Monte － Carlo simulating method．