A calculation method for the heat transfer process of porous pyrolysis materials, including deriving the mass, momentum and energy conservation equations of each layer inside the composite material, realizing the solution of the mass, momentum and energy equations of the solid phase and gas phase inside the porous medium structure, and obtaining the solid phase temperature T, density ρ, thermal conductivity ks, gas phase density ρf, thermal conductivity kf, porosity φ, pyrolysis gas pressure p, decomposition gas overflow velocity un. The invention can analyze the heat transfer process of different kinds of carbonized pyrolysis materials, can display the pyrolysis process of the pyrolysis gas inside the material in three dimensions, obtain the pressure and velocity distribution of the pyrolysis gas, and the cloud map of the temperature distribution of the porous medium structure formed after pyrolysis . By calculating the heat transfer process of porous pyrolysis materials, it solves the problem that it is difficult to accurately calculate the temperature of composite materials and the ambient temperature in the cabin of hypersonic aircraft.