Heat pump steam engine

The invention relates to a steam engine, in particular to an improved structure of a heat pump steam engine. The heat pump steam engine is characterized by comprising a heat pump system, a plate heat exchanger (5) connected with the heat pump system through a reversing valve (4), a fin type heat exchanger (10) of which one end is connected with the heat pump system through the reversing valve (4) and the other end is connected with the heat pump system through a first control device and a second control device, and a steam generating system connected with the plate heat exchanger (5). Therefore, the invention has the advantages that: the heat pump steam engine has an obvious energy-saving effect, has no waste smoke and gas emission and does not pollute the environment.