Thermal desorption is one of the efficient technologies for contaminated soil remediation, which can repair the site soil after organic matter (or volatile inorganic matter) contamination, and can achieve a good remediation effect. The implementation methods can be divided into ectopic and in situ thermal desorption. Ectopic thermal desorption heats the soil contaminated by organic matter above the boiling point of organic matter by direct or indirect heating, so that the pollutant can be volatilized into gaseous state and then separated and treated. The treated soil can be backfilled and then continue to be used. The ectopic thermal desorption technology selectively volatilizes pollutants without damaging organic pollutants by controlling system temperature and material residence time, and can effectively remove volatile organic compounds, such as benzene series, chlorinated solvents, volatile petroleum hydrocarbons, aromatic hydrocarbons, etc.; less volatile, high boiling point and refractory organic pollutants such as polychlorinated biphenyls, DDT, organochlorine pesticides and dioxins can also be effectively removed, and organic pollutants with a variety of different boiling points can be heated at one time to achieve the remediation target value.