Abstract: Red bed landslide disaster is widespread to the Northern mountainous expressway in Sichuan province.According to the field exploration on Guangyuan-Bazhong expressway,the formation mechanism of landslide is analyzed through landforms,rock character,geologic structure,hydrological geology and landslide morphology,so the type of the landslide is proved to be sliding-traction.Through the analysis and calculation of the landslide,the stable coefficient K ranges from 1.05 to 1.15,the front part of the landslide is in river bed which suffers flood flushing,and the ramp cutting and foundation pit excavation is harm to the landslide stability,which causes the decrease of stable coefficient in to a critical state,so the landslide needs to be reinforced.Combined with the engineering practice,treating measures are putting forward which are piles setting to the front part of secondary landslide,small diameter steel pipe piles setting to the backside of first order landslide,and assisting with draining and intercepting of water.