In order to study the effect of well pattern infilling on enhancing gas recovery of carbonate gas reservoirs, taking the T₂l₁¹ gas reservoir of Moxi gas field in Sichuan Basin as an example, a set of large-scale 18-meter physical simulation experimental device and method are established. The experimental model have a permeability of 0.56×10^-3 μm² and single well exploitation and well infilling (Well 1 and Well 2 are deployed at 14.1 m (78.3%) and 4.6 m (25.6%) from the initial well, respectively) exploitation have been simulated based on the model. The experiment measure gas production and pressure throughout the entire life cycle, revealing the reserve utilization laws under different water saturation conditions of the gas reservoir. The study compares and analyzes the effects of batch and simultaneous infilling methods, as well as the timing of two infilling methods at the end of stable production and under abandoned conditions, on improving the recovery efficiency of the gas reservoir. The experimental results show that: (1) For single well exploitation, gas recovery is significantly affected by water saturation, showing a significantly decrease with increasing water saturation. The recovery is 14.6% to 64.7% under the condition of water saturation of 20%-50%; compared with single well deployment, the rate of recovery can increase to 85.9%-92.7% after two wells are infilled, and the effect of infilling is significant. (2) Infilling wells enhancing gas recovery have two functions: one is to improve the production range of reserves in the undeveloped area, and the other is to improve the pressure drop efficiency in the developed area. The production of gas reservoir reserves is closely related to the water saturation and the distance from the gas well. The well pattern infilling can be deployed according to the production of reserves, and the undeveloped area and the developed (insufficient) area of reserves are preferred. (3) The enhancement of recovery rate through the deployment of infilling wells initially increases and then decreases as the number of well increases. Therefore, it is recommended to optimize the number of infilling wells in developed areas based on the characteristics of the remaining reserves in the gas reservoir, avoiding excessive infilling. Further analysis from the perspectives of enhanced gas recovery range and exploitation efficiency shows that adopting a centralized deployment of infilling wells and simultaneous infilling at the end of stable production period is more beneficial for extending stable production period, improving recovery, and shortening production cycle. The research results can guide the deployment of well pattern infilling in gas reservoir to enhance gas recovery.