With the development of industry and technology, multi-element gases coexist in many places. The study of the influence of appropriate concentration of flammable gas on the chemical kinetic characteristics of methane-air explosion is great significance for preventing and controlling gas explosions. An experimental system was set up to carry out different concentrations of C3H8/H2/CH4/air premixed gas explosion. The effects of multiple gases on the methane explosion characteristic parameters were studied. It is shown that the pressure peak firstly increases and then decreases with the increase of propane concentration when the C3H8/CH4/air mixture gas explosion experiment is carried out. The explosion of propane/methane/air mixture is most significant when the propane concentration is 0.4%. The experiment of H2/CH4/air mixed gas explosion was carried out. With the increase of H2 concentration, the pressure peak increased gradually. In the experiment of C3H8/H2/CH4/air mixed gas explosion, the peak pressure firstly increases and then decreases with the increase of propane concentration. C3H8/H2/CH4/air mixture gas explosion is most significant when the concentration of C3H8 is 0.2% and the concentration of H2 is 1%. The elementary reactions process were numerical simulated by CHEMKIN-PRO software. The micro-mechanism of multi-element gas explosions based on key radicals, sensitivity and reactions paths. Reaction step R38: H+O2<=>O+OH and R53: H+CH4<=>CH3+H2 to affect the explosion process. 0.1%C3H8+1%H2 and 0.2%C3H8+1%H2 will accelerate the CH4/air premixed gas explosion reaction rate, 0.3%C3H8+1%H2 will inhibit the methane/air premixed gas explosion reaction rate. It is mainly because R312 elementary reaction at this concentration: CH3+C2H5(+M)<=>C3H8(+M) dominates the explosion, inhibiting R38 elementary reaction: H+O2<=>O+OH, reducing OH the amount of production, thereby inhibiting the explosion process. The research results have important practical value for preventing and controlling multi-element gas explosion accidents and reducing accident losses.