The invention provides a device for recycling waste heat of an engine exhaust pipe so as to improve comprehensive oil consumption utilization rate of an engine. The device comprises an ethyl alcohol supply device A, an ethyl alcohol catalytic device B and an ethyl alcohol supply device C; the ethyl alcohol supply device A comprises an ethyl alcohol box, a connecting pipe, a liquid pump and an overflow valve; the ethyl alcohol catalytic device B comprises an evaporator, an energy storage device, a connecting pipe, a gas pump, a catalyst and an exhaust manifold; the ethyl alcohol supply device C comprises a connecting pipe, a water draining valve, a separator, an air inlet manifold and the engine; an evaporation chamber of the evaporator, the gas pump, a catalytic cavity of the catalyst, the separator, the air inlet manifold and an air inlet of the engine are sequentially connected in series. The energy storage device is in parallel connection to the position between the evaporator and the gas pump, an air outlet of the engine, the exhaust manifold, a waste gas pipe of the catalyst and a three-element catalytic chamber of the evaporator are sequentially connected in series. Heat energy of waste gas exhausted by the engine can be recycled and reused, meanwhile, dual fuel is provided for the engine, energy is saved and meanwhile emissions of pollutants can be reduced.