Heat pumo's drying process is a huge energy-consuming process. According to statistics, in most developed countries, the energy consumed for drying accounts for the country's total energy consumption, and the thermal efficiency is only 25%-50%, and most of the drying The process especially affects heat-sensitive materials (such as food and biological materials) on its color, nutrition, flavor and organization. The heat pump drying technology has the advantages of low energy consumption, low environmental pollution, high drying quality, and wide application range. Its excellent energy-saving effect has been proved by various experimental researches at home and abroad.