The utility model relates to the technical field of energy saving, in particular to a phase-change heat exchanger temperature difference generating device. Semiconductor temperature difference generating sheets which are in serial connection or in serial and parallel connection are arranged between the excircle arc surface of a phase-change heat exchanger and the inner circle arc surface of a finned radiator, the low temperature surfaces and the high temperature surfaces of the semiconductor temperature difference generating sheets are coated with high-heat-conduction silica gel, a temperature-preserving material is filled in other gaps between the phase-change heat exchanger and the finned radiator, a phase-change energy-storage material is sealed in a phase-change energy-storage material containing cavity of the phase-change heat exchanger, and the finned radiator I and the finned radiator II in the finned radiator are connected through connecting pieces. In the utility model, by utilizing the temperature difference between high temperature waste gas and the outside world, and the phase-change energy-storage and temperature difference generating technology, and the energy of the waste gas is fully utilized, and is converted into electrical energy. The phase-change heat exchanger temperature difference generating device disclosed by the utility model has high waste heat utilization rates and generating efficiency, simple structure and convenient installation, and can be widely used for recovering the waste heat of the waste gas of boilers, the high temperature tail gas of automobiles and the like.