The difference of porosity and permeability of rear-flat carbonate gas reservoirs in northeast Sichuan is very great, the heterogeneity is strong, and the pertinence of acidizing process design is not strong. Based on the calculation model of the effective distance of acid solution and the conductivity of acid corrosion crack, a set of prediction chart of acidizing effect and optimization method of process parameters are established. Based on the characteristics of reef-flat carbonate reservoirs in northeast Sichuan, the optimum design of acidizing process parameters for different types of reservoirs was carried out, and the field case was verified. The work not only has guiding significance for the efficient development of reef-flat carbonate rocks in northeast Sichuan, but also provides theoretical and practical reference for the optimization of acidizing process of carbonate rocks under similar geological conditions.