The issue of casing deformation becomes significant when in-situ stress is redistributed due to the large-scale volume fracturing of shale gas horizontal wells. However, there needs to be more appropriate solutions for preventing and controlling casing deformation in practical applications. This study utilizes microseismic, logging, and post stack seismic data to analyze the casing deformation characteristics of shale gas wells in the Weiyuan Block of the southern Sichuan Basin. The objective is to understand the casing deformation mechanism and identify the main controlling factors. Additionally, the study aims to develop casing deformation risk assessment templates and propose targeted preventive and control measures to mitigate the risk of casing deformation. The analysis demonstrates that: (1) the fault slip state of in-situ stress in this block is produced by shear deformation of the casing. (2) The casing cannot meet the requirement of the bridge plug passing through the casing when it experiences radial fracture during the indoor mechanical test. The casing’s diameter becomes irregular and oval, and its minimum inner diameter drops by 34 and 29 mm, respectively. (3) creatively create the casing change risk model, ant body tracking-fault slip identification, and multi-cluster fracturing model, which may direct horizontal shale gas well multi-cluster fracturing design. (4) Methods have been devised to integrate preventive and therapeutic approaches for casing-variable portions in horizontal shale gas wells. To mitigate the hazards associated with these areas, preventive measures such as controlled fracturing and temporary plugging of the ends of the seams have been proposed. Furthermore, the suggested techniques involve exerting pressure on extensive portions and fracturings by employing compact bridge plugs to traverse deformed casing segments. Process controls, such as accelerating perforations at anomalous sections and regulating the fluid flow at faults, were devised to prevent casing change in the field. Field experiments were conducted in the Weiyuan area of the southern Sichuan Basin to evaluate the effectiveness of “ant body tracking-fault slip identification of set risk” and other techniques. A total of 28 wells were included in the study. The results showed a significant reduction in the rate of casing deformation, decreasing from 54% prior to the study to 14.3%. Additionally, the rate of lost sections decreased from 7.8% before the study to 0, indicating notable improvements in set loss.