There are many ways to dry wood. According to the discharge method of moisture in wood, it is divided into three types: thermal drying, mechanical drying and chemical drying. The actual wood production process uses thermal drying. Thermal drying can be divided into atmospheric drying (referred to as air drying, also known as natural drying) and artificial drying according to whether the drying conditions are artificially controlled or not. Artificial drying can be divided into kiln drying (including low temperature, conventional and high temperature kiln drying), dehumidification drying, solar drying, vacuum drying, high frequency and microwave drying, infrared radiation drying and contact (hot pressing) drying. These drying methods are outlined below.