In order to meet the national environmental protection standards and propose a safe, reliable, economic, applicable way of floor seepage control, and to effectively protect the soil, groundwater and surface water from pollution, this paper through physical and chemical properties analysis in the process of natural gas purification plant, combined with the different function of production equipment, has made a reasonable division for pollution control areas to determine the seepage control design, to meet the needs of the project and exactly follow the requirements of environmental protection. According to the engineering practice of a natural gas purification plant, a rigid anti-seepage method suitable for the project is put forward to meet the project and the environmental assessment and acceptance. However, there are few applicable standards and specifications at present, and it is proposed to be improved.