Hot air circulating drying oven applies a low-noise and high temperature-proof axial flow blower and an automatic temperature control system which is fully sealed, making that the heat efficiency of the drying oven increases from 3-7% of traditional oven to 35-45% of the present one, the highest heat efficiency can reach 50%. WKS series special drying oven adopts the axial flow fan, with automatic constant temperature control system. Its thermal efficiency is more than 95%, which uses electricity as heating source and adopts convective heat transfer method to heat the air by axial flow fan and heat exchanger . Fresh air from the air inlet supplement, waste damp is out from the dehumidification system. Constantly add fresh air and discharge damp to keep the correct relative humidity in the oven. The biggest characteristic of this series of drying oven is that most hot air is cycling in the cabinet, the entire cycle is closed, so as to enhance the heat transfer, saving the energy.