Waste heat refers to the heat energy generated in the process of industrial production, which is not utilized and discharged. It is secondary energy carried in solid, liquid and gas medium such as slag, waste water, circulating water, spent steam and smoke. Middle and high temperature waste heat recovery technology is relatively simple and widely used, but low grade waste heat with low temperature has huge recover space, but it is difficult to recovery. Together with Tsinghua university and Xi’an Jiaotong university, THT has carried out the research and development of waste heat recovery technology and mature waste heat recovery and utilization integrated system can recover and comprehensively utilize these low-grade waste heat. At present, it has been applied to flue gas recovery and treatment, and gradient utilization of geothermal water, waste heat utilization of industrial and civil sewage, heat recovery and utilization of industrial circulating cooling water, heat recovery and utilization of industrial waste water, combined heat supply and capacity expansion and other fields.