In order to further reveal the process of rainfall infiltration and stability evolution of bedrock-type stepped high cutting slopes under rainfall cycling conditions, taking the bedrock-type stepped high cutting slope of a silty clay cover layer from Mabian to Zhaojue section of Lexi Expressway as the research object, a mathematical model for the deterioration of soil shear strength parameters was established through indoor dry-wet cycle tests; Geo-studio numerical simulation software was used to study the rainfall infiltration process of the high cutting slope under multi-case rainfall cycles, which reveals the internal seepage field and stability change rules of high cutting slopes under different rainfall cycle conditions and after rain. And the annual degradation equation of the stability coefficient of the rainfall-type high cutting slope has been established; Combining the results of indoor experiment and numerical simulation, a method for predicting the stability coefficient of this type of high cutting slope has been established. The research results show that the shape and position of the potential sliding surface of the high cutting slope does not change significantly during the process of rainfall infiltration, and it appears as a combined sliding surface of the circular surface and the bedrock water surface at the depth of the high cutting slope; In the same rainfall period, the depth of rainfall infiltration and the extent of stability degradation of high cutting slopes are positively correlated with rainfall intensity; The degree of stability degradation of high cutting slopes in a single rainfall cycle is negatively correlated with the number of rainfall cycles. The greater the depth of rainfall infiltration or the total rainfall infiltration of high cutting slopes, the smaller the recovery of the stability coefficient of high cutting slopes after rain; It is relatively safe and reasonable to use the average value of the degradation coefficient of the shear strength parameter of the soil for the degradation coefficient of the high cutting slope stability coefficient. And the prediction method for the stability coefficient of rainfall-type high cutting slope has high accuracy.