The split refrigerant circulating dryer reduces the air temperature flowing through to below the dew point temperature, thus reducing the absolute humidity and water extracting from the air (condensate is discharged out of the drying room by drainage pipes);Reuse heat pump condenser to heat air, increase air temperature, reduce relative temperature, and generate high temperature and low humidity dry air. Dry air flows through the material and takes water back to the evaporator again, forming a drying cycle and completing the drying of material after several drying cycles.