With the continuous development of the geothermal well construction in recent years, the demand of casing for geothermal well is also increasing steadily. Because the construction cost of geothermal well using oil casing keeps growing, it is urgent to develop a special casing for geothermal well to adapt the needs of geothermal well construction with low cost. According to the characteristics of the geothermal well construction and the performance requirements to the casing, a low-cost casing for thermal well is developed. The paper mainly introduces this casing about its structure form, technical parameters, process equipment and production application.