Abstract: Refuse derived fuel is widely used in drying engineering,cement manufacturing,heating engineering and power generation engi-neering. The mechanical grate incinerator has the problems of high investment cost,high maintenance cost,large floor area and large heatloss.The gasification incineration technology is still in the laboratory or semi industrial stage,which can not realize the industrial applica-tion.The rotary kiln incineration requires high waste heat value,and the slag index is easy to exceed the standard,so it is rarely used in in-dustry.Therefore,in view of the characteristics of fluidized bed boiler,such as large furnace heat capacity,intense mixed combustion in thefurnace and strong fuel adaptability,it is necessary to study the incineration process of waste derived fuel,biomass and solid waste. Startingfrom the aspects of combustion mechanism,material preparation and transportation,the research and development of key technologies,process optimization and core component design of direct mixed combustion of garbage in CFB boiler were completed through theoretical re-search,numerical simulation,combustion test,equipment research and field test,and the application of this technology in large-scale CFBboiler was verified. The results show that the complete and stable combustion of MSW and the decomposition of dioxin can be promoted by ensuring the incinerator temperature and residence time(more than 2 s) and increasing the turbulence degree(Re>5 000) in the incinera-tor. In order to reduce the content of combustibles brought to the tail flue,it is necessary to improve the burn out of garbage fuel during op-eration,so as to avoid the accumulation of ash and secondary combustion caused by the condensation of incompletely burned organic mole-cules at the position of air preheater. Through theoretical analysis and test,the final choice is to use pneumatic conveying system to sendthe crushed biomass and solid waste into the furnace,and the boiler interface is arranged at the outlet of the feeder to meet the needs of bi-omass and solid waste combustion time,temperature,mixing,burnout,etc. The practical operation results show that the 300 MW CFB boil-er can simultaneously treat 200 t/d biomass,400 t/d solid waste,200 t/d sludge and 50 t/d RDF. The emission concentration of dioxin inthe flue gas is lower than 0.001 3 ng/m~3(standard,11% O_2),the emission of SO_2 is lower than 12 mg/m~3,and the emission of NO_x is lower than 50 mg/m~3,which meets the relevant standards. The system can burn 120 000 tons of solid waste in one year,which can saveenergy equivalent to 85 500 tons of standard coal,and reduce emissions of 237 000 tons of CO_2,726.8 tons of SO_2,632.7 tons of NOx and33 500 tons of ash. It can dispose a lot of solid waste in a short time,and solve the important problems such as direct burning of straw inthe field,siege of sludge and garbage.