To achieve the integration of renewable energy utilization and CO₂ emission reduction technology, high-temperature gas field geothermal resource extraction was conducted via the CO₂ plume geothermal system, which merges the benefits of CO₂ sequestration with deep geothermal resource development, facilitating the concurrent sequestration of CO₂ during thermal extraction. Taking a high-temperature gas field as the target thermal storage, a three-dimensional thermal flow coupling model of cap rock thermal storage bedrock was constructed using COMSOL software to analyze the thermal compensation effect of the rock mass on both sides of the thermal storage and the relationship between the number of production wells and the system's thermal recovery performance. The findings indicate that during the advanced phases of the plume geothermal system's operation, when thermal compensation is considered, the fluid's temperature decline rate diminishes, resulting in an enhanced heat extraction rate and a greater heat extraction resource, while the thermal storage extraction degree is reduced, thereby extending the system's operational lifespan. It was discovered that increasing the number of production wells resulted in a smaller production fluid temperature decline. The operation of a CO₂ plume geothermal system demonstrates that the thermal compensation effect of cap rock and bedrock on thermal storage, along with an increase in the number of production wells, can extend the system's lifespan, offering theoretical insights for the optimisation and practical implementation of CO₂ plume geothermal systems in the future.