Heat pump is an energy-saving device that uses high-level energy to make heat flow from low-level heat sources (air, water, etc.) to high-level heat sources. It can convert the low-level heat energy that can not be directly used into the high-level heat energy that can be used. Compared with the traditional energy sources, it is helpful to achieve significant energy-saving. Compared with the traditional heating and cooling methods, the application of heat pump in building can save more than 40% energy. Heat pump products are mainly divided into air source heat pump, water ground source heat pump and industrial high temperature heat pump. Variable component heat pump unit with non azeotropic mixture can provide heating, cooling and hot water at the same time. Frequency conversion technology is used to improve the seasonal performance. It has high operation efficiency under different working conditions. It is more conducive to the soft start of power grid and the reduction of starting current. There is no chemical change in the operation process, and there is no pollution to the atmosphere and environment.