Abstract: Taking a homogenous soil slope as example, orthogonal design test method and numerical processing method for principal component analysis were used in the principal component analysis of the factors influencing slope stability, which overcame the difficulty of a large amount of calculation in conventional methods, considered the interaction between factors and gave quantitative contribution of each principal component to slope stability.The investigation shows that for commonly seen homogenous soil slope or loose-stacked rock-soil slope, cohesion, angle of friction and slope height have the greatest contributions to the slope stability; and in the rock-soil mass area with a seismic fortification intensity of below seven degrees, soil density and seismic acceleration have the least contributions to the slope stability.

Key words: Slope stability, Influence factors, Orthogonal design, Principal component analysis