Site environment itself can not meet the purification capacity and the rate of pollution caused by the pressure on the environment, researchers and relevant departments began to focus on site pollution control and repair technology research. On the basis of self-purification of the site environment, various contaminated sites are rehabilitated and purified in accordance with the pollution characteristics of contaminated sites, land functions, groundwater environment characteristics and various physical, chemical, biological and complex modes and technologies. At present, the system of remediation of contaminated sites, which is widely used, mainly includes physical remediation technology, chemical remediation technology, bioremediation technology and joint (integrated) remediation technology in accordance with the principles of rehabilitative technologies. 1, physical repair technology Physical means as the main removal, covering, dilution, thermal evaporation and other pollution control technologies. Mainly include physical separation technology, soil steam extraction technology, curing / stabilization technology, glass technology and thermodynamic repair technology. 2, chemical repair technology Use of foreign, or soil between their own substances, or changes in environmental conditions caused by chemical reactions to pollution control technology. Including chemical oxidation, chemical leaching method, chemical improvers, solvent extraction technology. 3, bioremediation technology Broad-based bioremediation refers to all technologies that utilize organisms as the mainstay of environmental pollution control, including the use of plants, animals and microorganisms to absorb, degrade and convert pollutants in the soil to reduce the concentration of pollutants to acceptable levels; or Toxic, harmful pollutants into harmless substances. Broad-based bioremediation includes microbial remediation techniques, phytoremediation techniques, and remediation techniques that take soil animals as their main function. The narrow bioremediation refers specifically to the removal of contaminants in soils by the action of microorganisms or the detoxification of pollutants. 4, joint (integrated) repair technology Due to the complexity of the soil pollution system caused by heterogeneous anisotropy of soils and the particularity of soil pollution, the single repair technique is often difficult to achieve the purpose of effective restoration and purification. In addition, in the soil system, the physical, chemical and biological processes themselves are also difficult to separate. Therefore, the joint remediation of contaminated soils is often involved and adopted in the systems of remediation and remediation of contaminated soils. The main principles include physical-chemical combination, chemical-biological combination, and physical-chemical-biological combination In the soil environment system, through a variety of mechanisms and processes, the removal of pollutants in the soil environment, the contaminated soil repair and purification.