The invention discloses a loess high slope stability analysis method suitable for the rainfall condition. According to the loess high slope stability analysis method, based on the Sweden slice method, the situation that a sliding surface passes a back edge fracture end point and the position of 1/3 h of a slope surface is assumed, and meanwhile, the influence of rainfall weight increment and loess water content change on the loess slope stability is considered. The loess high slope stability analysis method comprises the basic steps that 1, the loess c (w) and phi values are measured; 2, the depth of a back edge fracture is calculated; 3, the circle center range of an arc failure surface is determined; 4, circle centers and loess bodies separated in a striped mode are selected; 5, the rainfall weight increment coefficient Ki is calculated; 6, the safety coefficient is calculated; 7, the different circle centers are selected by returning to the step 4 till the minimum safety coefficient is calculated; and 8, the water content value is changed, the step 4 is returned, and the minimum safety coefficients under different water contents are calculated. The loess high slope stability analysis method suitable for the rainfall condition is simple and practical, the related calculating parameters are clear in significance and easy to acquire, the problem of the stability estimation of a loess high slope can be effectively solved, and accordingly corresponding geological disaster hidden dangers are eliminated.