The invention provides a multistage compression and stepwise heat utilization steam compression heat pump, which belongs to the technical field of waste heat utilization and heat pump refrigeration. Aiming at the shortcomings of the single condensation to heat release unit in stage compression and inter-stage cooling, the heat pump provides the steam compression unit which comprises two or more compressors, two or more condensers, an evaporator and a throttle valve, and the steam compression unit can implement condensation and heat release to outside respectively by each compression and heat moving flow. A low temperature compression and heat release flow is composed of a low-pressure compressor and condenser, a throttle valve and a evaporator; a high-temperature compression and heat moving flow is composed of a high-pressure compressor and condenser, a throttle valve and other parts by virtue of the structure of the low-temperature compression and heat moving flow; the residual heat medium can release heat by flowing through the evaporator; the heat medium absorbs heat by flowing through the each compression and heat moving flow. The multistage compression and stepwise heat utilization steam compression heat pump has the advantages that: the heat transfer temperature difference is reduced; the unit performance index is improved; while being used as a heat pump, the heat pump is particularly suitable for the occasion with high heat supply temperature and wide range, and can be used for refrigeration and power consumption reduction.