Abstract: In recent years,the amount of harmless waste incineration treatment in China has been increasing year by year. With the increasing amount of fly ash generated after garbage incineration,the heavy metals and other harmful substances in fly ash have great pollution to the environment. Taking the municipal solid waste incineration (MSWI) fly ash produced by a municipal solid waste power plant in Taiyuan as the research object,The samples of ash/coke (6∶1) and ash/coke (9∶1) were melted at 1 700 ℃ in an ultra-high temperature plasma gasification melting furnace,and the composition,microstructure and element distribution of MSW fly ash and molten glass slag were characterized and analyzed by XRF,XRD and SEM-EDS. The study shows that the metal chlorides in the fly ash of MSWI mostly exist in the form of Na Cl and KCl,accounting for about 5% of the composition of the fly ash. High temperature melting is conducive to the gasification of chlorine salt in the fly ash of MSWI,and the content of chlorine salt in the fly ash of MSWI is reduced. The fly ash is mainly flocculent and spherical,and the surface is enriched with many metal elements. can The acid oxide Si O2 in the fly ash can be recombined by the high temperature melting,which realize the encapsulation of heavy metals. The leaching amount of molten glass slag after melting is lower than the leaching toxicity standard of various countries.The high temperature melting at 1 700 ℃ will make the high temperature resistant material ZrO_2 fall off inside the furnace,leading to a shorter service cycle. The basicity coefficient is the main reason affecting the melting temperature. The reduction of basicity coefficient can reduce the melting temperature. It is necessary to further adjust the basicity coefficient so as to reduce the melting temperature in the furnace and extend the service life of ZrO_2. Therefore,before melting treatment,the characteristic temperature of the ash melting point of the sample can be determined,and the melting temperature of the melting furnace can be set accordingly to avoid the falling off of the insulation material due to the high temperature.