Natural gas exploration in deep-sea carbonate rocks in the Sichuan Basin has been effective, but the reservoir of the Mesozoic-Triassic Leikoupo Formation has been less studied, and the rock mechanical properties required for reservoir modification are not clearly recognized. Through the rock static acid etching test and combined with the rock mechanical properties test, we investigated the influence of acid on the rock mechanical properties of carbonate reservoirs of different characteristics, and explored the modification effect of different acid systems on the reservoir rocks. The test results show that the acid has a great influence on the physical and mechanical properties of the rock, the triaxial compressive strength and elastic modulus of the rock decrease with acidification, and the damage mode still shows tensile cleavage damage, but the damage mode has a tendency of brittleness to ductility transformation. This study can help to guide the design and optimise the technical parameters of acid pressure reforming in the field reservoir, which is of great technical significance for the improvement of acid pressure reforming technology in carbonate reservoirs.