In recent years, with the continuous progress of reservoir transformation technology, the development of fractured-vuggy reservoir for carbonate gas reservoirs has attracted much attention. Compared with conventional carbonate reservoirs, although fracture pore type reservoirs have more developed fractures and cavities, its reservoir heterogeneity is strong, the storage space is complex, and working fluid leakage is easy to occur during drilling and completion. In particular, the permeability level difference between the working fluid leakage section and other reservoir sections is very large, making it difficult to achieve uniform transformation of the reservoir section. Therefore, in view of such highly heterogeneous reservoirs, this paper takes the fourth Member of Dengying Formation in the Gaoshiti Moxi block of Sichuan Basin as the research object, with the goal of improving the utilization degree of tight reservoirs with low permeability and achieving uniform reservoir transformation. Through the laboratory experiment of reservoir transformation technology, the transformation effect of self-diverting acid on reservoirs with different permeability contrast was evaluated, and the experimental evaluation of the transformation effect of the composite acid system of self-diverting acid + gelling acid under different alternating ratios was carried out. A composite acid fracturing transformation technology for strongly heterogeneous carbonate reservoirs was proposed and its parameters were optimized. Combined with software simulation and field application, it is proved that the technology is scientific and feasible, and the ideal effect is obtained in field application.