The electric heating constant temperature blast drying box is composed of a box body, an electric heater, a temperature controller, a fan, a wind convection circulating air duct, an air inlet duct, an air outlet duct and an air outlet size adjusting device. The electric heating constant temperature air drying oven is heated by an electric heater. Generally, the heating wire exposed to the air is easily oxidized due to high temperature and long-term heating, which affects the service life. The heater of our company usually adopts a coil type electric heating tube, that is, the heating wire is located in the heating tube. Internally, it can reduce the oxidation rate and increase the life, while the heat is transferred to the steel pipe to increase the heat transfer area. The drying oven temperature controller is used to control and display the temperature. When the temperature inside the box is lower than the set temperature, the temperature controller controls the heater to continuously heat or the gap heats, so that the temperature inside the box reaches a controllable purpose. The function of the blower fan is to convect the air level in the dry box (desktop electric blast drying oven) or vertical (vertical blast drying oven), so that the air in the box is blown onto the electric heater and heated to the studio. Then, the fan is sucked into the fan by the working chamber and then blown to the electric heating tube for heating, and the temperature in the box is more uniform while continuously circulating and heating. The hot air in the studio heats the wet sample, and the water becomes heated into water and steam into the hot air. One of the functions of the blast fan is to circulate the air in the box. The second effect is to continuously suck in a part of the fresh air outside the box into the heating cycle of the box from the uniquely designed inlet air duct without affecting the temperature in the working chamber. While a certain volume of external air is sucked in, an exhaust gas having the same volume of water vapor is discharged from the vent hole out of the tank. The amount of air exchange inside or outside the tank (or exhaust gas rate) can be adjusted by changing the size of the outlet. Through the constant exchange of indoor and outdoor air, moisture is also taken out of the box to achieve the purpose of drying. Guangzhou Fuerle Health Technology Co., Ltd , https://www.fuerlehealth.com