Abstract: The propagation of methane explosion in a long closed pipe was simulated by the AutoReaGas software and the effect of methane concentration on explosion overpressure was studied. The effect of the number of obstacles and the blocking rate on the explosion overpressure and law of flame propagation were investigated. The numerical simulation results show that in the pipe without obstacles, the overpressure of the methane explosion is maximal when the gas concentration is stoichiometric; in the pipe with obstacles, the flame velocity initially increases and then decreases with the number of obstacles increasing. When the number of obstacles is fixed, the maximum explosion overpressure and the flame velocity increase with the blocking ratio increasing.