The joint effect of earthquake and rainstorm is the extreme condition which causes landslide in nature.The current co des to evaluate the impacts of both earthquake and rainstorm on slope stability are just a simple addition of the two factors.By using the GEOSLOPE software and employing dynamics element infinite and limit equilibrium theory,this paper evaluates the stability of the typical slope sites along the Sichuan—Tibet highway and Xichang—Panzhihua freeway under the coupling of earthquake and rainstorm,in order to find the difference of simple addition and the coupling analysis of earthquake and rainstorm,and also evaluates the applicability of regular computational methods.Research has found that the coupling of earthquake and rainstorm has more serious impacts to slope stability than the simple addition of impact of earthquake and rainstorm alone.