The terrain and geological conditions around Sichuan Basin are complex, and the engineering diseases of bedding slope in highway construction are frequent. Through engineering geological analysis and numerical calculation, based on the damage constitutive model of the sliding surface, the variation law of the characteristic quantities such as the stress, displacement, and slope stability coefficient of the sliding surface before and after the bedding slope support were studied, and the applicability of the pile-anchor composite structure to reinforce the bedding slope was verified. Then, through the on-site monitoring of the whole construction period, the time-effect characteristics of the deep displacement of the slope, the bending moment of the anti-slide pile and the stress of the anchor cable were obtained. The results show that the bedding slope has progressive failure characteristics under excavation disturbance. From the slope toe along the sliding surface to the trailing edge, the displacement decreases exponentially and smoothly, the shear stress increases first and then decreases, and the damage variable of the sliding surface begins to attenuate at the same frequency from the peak position of the shear stress. After the pile-anchor composite structure is used to reinforce the bedding slope, the maximum displacement of the sliding surface is reduced by 88.62 %, the maximum damage variable is reduced by 84.75 %, and the stability coefficient is increased by 25.20 %. The monitoring of deep displacement of slope, bending moment of anti-slide pile and anchor cable stress verifies the effective effect of pile-anchor composite structure reinforcement.