In order to prevent the risk of roadbed slope landslide during the operation of high-grade highways, this article is based on the risk assessment theoretical model, relying on an example of an expressway roadbed instability event, combined with on-site survey and detection data and mathematical simulation calculations, and the occurrence rate of roadbed slope landslides is obtained 21% and a safety factor of 1.04; based on the risk assessment, the corresponding three types of roadbed slope landslide treatment plans were proposed from the three angles of the upper, middle and lower parts of the slid body; comprehensive comparison of the occurrence rate and economic benefits of landslides after treatment Factors, the best comprehensive treatment plan of the slope surface anchor rope frame beam support combined with the prestressed anchor rope anti-slide pile support is selected; finally, the effect of the roadbed slope after treatment is evaluated. The research results of this paper can provide a perfect experience reference for the risk assessment and treatment of related roadbed slope landslide disasters.