Abstract: In order to solve the problem of carrying H₂ on vehicle, this papper proposes a new method to produce H₂ on board by using energy of engine exhaust heat to support methanol steam reforming.The engine thermal efficiency can be largely improved and engine pollutants, thermal and noise emissions can be further reduced by the mixed combustion of fuel and the hydrogen-rich reformed gas inducted into the cylinders produced by this method.In this paper an apparatus was designed to produce hydrogen-rich gas by methanol steam catalytic reforming using engine exhaust heat.The reformed reactor was basd on a porous ceramic substrate using Cu/Zn/Al/Zr as reforming catalysts and a tube-type heat exchanger to heat the ceramic reactor to accomplish the reforming reaction of methanol/water solution in the ceramic pores.The engine test showed that hydrogen volume fraction in the reformed gas increased with the engine exhaust temperature and reached a maximum of 41.9%at the exhaust temperature of 350℃.