During the process of gas reservoir exploitation, as the reservoir pressure decreases, the effective stress on the reservoir also increases, which in turn affects the fluidity of the rock. Studies both domestically and internationally have shown that porosity changes with effective stress, but the magnitude of this change is not significant and can be neglected in practical calculations for oil and gas reservoirs. However, the change in permeability is more pronounced, leading to a reduction in the reservoir's flow capacity, and its stress sensitivity cannot be ignored. Sensitivity studies are particularly important for understanding the porosity and permeability characteristics of heterogeneous carbonate rock reservoirs. Since the formation pressure of ultra-high-pressure reservoirs is higher than that of conventional reservoirs, the effective stress variation range and stress sensitivity formed during the development process of ultra-high pressure gas reservoirs are different from those of normal pressure gas reservoirs. This paper integrates laboratory experiments conducted on reservoir samples from the X gas reservoir in the Sichuan Basin with digital core flow simulation analyses. The aim is to provide a comprehensive comparison and analysis of stress sensitivity in both conventional and ultra-high-pressure gas reservoirs. The study indicates that the overall stress sensitivity of ultra-high-pressure gas reservoirs is weaker than that of conventional gas reservoirs. Particularly, the stress sensitivity of fracture-vuggy type reservoirs is weak under the exploitation conditions of ultra-high-pressure gas reservoirs, but it is moderate to strong under the exploitation conditions of conventional gas reservoirs. The main reason for this phenomenon is that the effective stress variation amplitude during the exploitation process of ultra-high-pressure gas reservoirs is lower, preserving the primary seepage channels of the reservoir and resulting in smaller changes in flow capacity. This phenomenon is beneficial for maintaining stable production in such gas reservoirs under larger production pressure differentials compared to conventional gas reservoirs.