Double catalytic conversion devices of motorcycle muffler

Provided are double catalytic conversion devices of a motorcycle muffler. Each catalytic conversion device includes a muffling cylinder and a tail cylinder pipe in the muffling cylinder, The devices are characterized in that a fixing pipe is fixed at the inlet end of the tail cylinder pipe, two installing parts are arranged in the fixing pipe, each installing part is provided with four holes, and the catalytic conversion devices are fixed in the installing parts. The devices provided have the advantages of convenient fixing and high strength, and the devices not only can achieve the effects in noise and temperate reducing, but also can change harmful substances CO, HC and NO into harmless substances, thereby reducing the pollution to environment and improving the quality of atmosphere to enable the waste gases to meet the discharging standard.