Waste heat reclaiming device using Stirling engine

The invention discloses a waste heat reclaiming device using a Stirling engine, and particularly relates to a device for reclaiming thermal energy in waste gas of an internal-combustion engine to improve the efficiency of the engine. An internal-combustion engine exhaust pipe is connected with a gas side of a heat absorber in the Stirling engine, and one end of a working medium side of the heat absorber is connected with an expansion cavity through a plurality of short pipes; and the other end of the working medium side of the heat absorber is connected with a heat regenerator, and a power piston in the Stirling engine drives a generator to generate electricity through a set of transmission system. The heat absorber is designed with a plate fin type heat exchanger structure. The device has the advantages that the thermal energy discharged by the internal-combustion engine is converted into high-grade mechanical energy or electrical energy to be output, and the output energy is used for auxiliary devices of the internal-combustion engine such as an air-conditioning refrigerator, a water pump and an oil pump; and the power produced by the Stirling engine can be directly coupled with an engine crank shaft through a set of power coupling device so that the relative fuel consumption rate of the internal-combustion engine is effectively reduced.