In order to study the slope deformation law during and after the construction of the sandstone bed-cut high slope support project and the effect of the treatment project, this paper relies on a slope support project in Beijing to analyze the axial force of the anchor cable and the slope during the construction process. The slope displacement is monitored and analyzed, and the results show that the change of the axial force of the anchor cable is mainly divided into the acceleration loss stage, the fluctuation stage and the continuous stable trend stage; the change of the axial force of the anchor cable can well reflect the change of the internal force of the slope; the change of horizontal displacement and vertical settlement can reflect the change law of the deep displacement of the slope and the stability of the slope, has a better support effect. The finite element analysis software was used to simulate the excavation and support process of the sandstone-layered high slope. It was found that with the excavation of the slope, the displacement of the slope developed along the slope angle of the weak sliding surface, and the stability of the slope decreased. The monitoring results and the simulation results are compared and analyzed, and it is found that the change trends of the two are basically the same, which proves that the slope support system can effectively control the deformation of the slope. The research results can provide reference for the design and construction of similar slopes in the future.