Abstract: Recently, with the rapid economic development in the loess plateau, many engineering construction have to excavate in loess slope or landslide for side construction under the influence of the terrain, which has caused all kinds of deformation and failure in the process of slope excavation, and then bring serious harm. In this paper, we take a cut slope in Luoyang village, Fuxian as an example. Firstly, the slope failure mechanism in the process of slope excavation has been discussed by using qualitative analysis of engineering geology, and the deformation and failure process has been divided into three stages:the stage of differential deformation due to the toe of slope unloading, the stage of pressure cracking surface transfixion, and the stage of "V" type fracture stability. Secondly,the slope deformation and destruction characteristics have been described through combining with the finite element numerical simulation quantitatively. Finally, the maximum depth of creep portion has been calculated, which is about 93m from the shear opening and is consistent with the actual situation.