The percolation of coal-based gas in composite reservoirs is more complicated than that of single reservoirs. At present, the study of coal-bearing gas percolation models and laws is mainly based on a single reservoir, and the percolation model and percolation of coal-based gas in composite reservoirs. There are few regular studies. Based on this, a gas-soil gasification and percolation model of coal-sandstone composite reservoir was established, and the mathematical model was numerically solved by COMSOL numerical simulation software. The coal-sandstone composite reservoir coal system with or without interlayer turbulence was compared. Gas pressure recovery reservoir pressure variation law. The simulation results show that the existence of interlayer turbulence has a significant impact on the reservoir pressure changes in coal seams and sandstone layers. In the near-wellbore area, the coal-based gas flows from the sandstone layer to the coal seam. Considering the turbulent flow between the layers, the pressure drop of the coal seam reservoir is obviously reduced, and the reservoir pressure in the sandstone layer is not considered to increase significantly. In the wellbore area, the coal-based gas flows from the coal seam to the sandstone layer. Considering the turbulent flow between the layers, the reservoir pressure is obviously increased, and the reservoir pressure in the sandstone layer is significantly increased. The established coal-sand-sandstone composite reservoir coal-seated gas-collecting percolation model lays a foundation for the study of coal-based gas-gathering mining problems and has important theoretical value.