Nanhai Avenue, located in Nanchong, Sichuan, is a major urban road built along mountains. The project involves the comprehensive treatment of a high and steep slope, which is characterized by elevated height, complex geological conditions, and a large volume of landslide mass. Moreover, the newly constructed bridge structure that is present adjacent to the slope poses strict requirements for slope deformation control. Based on the high-slope project on Nanhai Avenue in Nanchong, in this paper, a finite element model is constructed using Plaxis software to study support measures for high slopes. The results reveal that in slope protection, anti-slide piles play a crucial role in bearing the majority of the landslide force, and after prestress is applied, frame anchor cables can significantly share the landslide force, reducing the displacement and internal force of anti-slide pile shafts. Frame anchor cables transfer the landslide force to deep anchored soil layers, significantly reducing the deformation of soil behind piles, which plays a key role in controlling deformation of the bridge adjacent to the slope and ensuring the safety of the bridge structure. It is anticipated that the results of this study will provide reference data for similar projects in the future.