The gas dynamic and kinetic scheme of methane pyrolysis in a reactor channel based on previously known schemes of hydrocarbon transformations in flames involving C1+, C2+, and C3+ species and including C4+ and free-carbon reactions is considered. The results of modeling are fitted to published data on methane pyrolysis. New results obtained with experimental model reactors at different pressures are reported. The influence of pressure on the acetylene-to-ethylene ratio at the reactor exit was studied.