On June 10, 2022, a 6.0-magnitude earthquake occurred in Caodeng Township, Marcang City, Aba Prefecture, Sichuan Province. The earthquake not only caused a large number of landslides and landslides, but also caused seismic cracking and deformation of the slope rock and soil mass. Taking the K39+280～K39+390 section of the newly built provincial road S220 from Ribu to Muerzha Bridge in the earthquake stricken area as an example, the rainfall disaster mechanism and prevention technology after slope seismic cracking and damage was studied. It is found that during seismic activity, the seismic Bora shear effect promotes the expansion of rock joints and fissures, leading to the relaxation of soil structures. As a result, seismic cracking damage is widespread and has a significant impact on slope stability. The pores, joints, and fissures in the rock and soil structure of earthquake damaged slopes have good permeability, which is conducive to rainfall infiltration, resulting in a rapid increase in soil moisture content during the rainfall process. Joint fissures continuously accumulate water, and the entire earthquake damaged deformation body gradually reaches saturation during the rainfall process, forming high-value water pressure near the potential failure surface. In addition, the lubrication and softening effects of pore water and joint fissure water reduce the frictional resistance between soil particles and rock structural surfaces, leading to a decrease in shear strength and promoting the stability of the deformation body to continuously decline until instability. Earthquake damaged slopes can be prevented and controlled by point surface combination. In areas with severe earthquake damage and deformation, frame anchor rods can be used for overall slope protection, while dangerous rock falling blocks are generally developed but relatively weak. The slope surface adopts the method of retaining at the foot of the slope (concrete retaining wall+steel grating) take protective measures.