Abstract: Landfill leachate from MSW incineration power plant contains a variety of harmful organic compounds and heavy metals. Concentrations of COD_Cr and BOD₅ are much higher than those of urban sewage, with high ammonia nitrogen content and strong stench, and thus thorough harmless treatment must be carried out. The current domestic landfill leachate treatment methods of most of the garbage power plants were biological treatment, physical and chemical treatment or their combined treatment methods. These methods were considered to be too complicated, expensive, and could not treat the contaminants thoroughly. The author traced back the source of landfill leachate. It was found that for a qualified waste incineration power generation boiler which was designed based on the data of combustion calculation and thermodynamic calculation by waste element analysis, the design parameters such as boiler power, efficiency, flue gas temperature could not be affected in theory, only when the leachate belonging to the waste into the furnace was fully misted and evenly sprayed into the furnace for complete incineration. Based on this point of view, the specific process of all leachate incineration was put forward in order to further improve the harmless incineration technology of refuse. The process included full misting of leachate, the number of spray entrances of atomized leachate and their corresponding positions and angles, and the way to automatically track and match the amount of leachate spray with the amount of incineration of reuse in the incineration.