According to the different drying materials, drying boxes are divided into two categories: electric blast drying box and vacuum drying box. Nowadays, they have been widely used in chemical industry, electronic communication, plastic, cable, electroplating, hardware, automobile, photoelectric, rubber products, mold, spraying, printing, medical treatment, aerospace and colleges and universities. The huge market demand makes the variety of drying oven diversified, and the product structure quality is not the same. In order to make people understand the drying oven more clearly, a pair of eyes are used to identify the quality of drying oven.