Abstract:in order to make full use of rich biomass resources, improve energy structure and realize energy saving and emission reduction, a kind of biomass gasification-coal coupling power generation unit process system is established in this paper through a 350MW coal-fired unit. Based on the principle of thermal power conversion and taking the characteristics of the biomass gasification-coal coupling power generation system into account, the thermal economy of the system is analyzed by equivalent enthalpy drop method. The analysis results show that the high temperature gasification gas produced by biomass gasifier can replace a large amount of coal and significantly reduce CO2 emissions. At the same time, the high temperature gasification gas after cooling down by the cooler can be recovered to 8th high pressure heater, which can further reduce the unit heat consumption and improve the unit efficiency. Therefore, compared with direct combustion biomass power generation, biomass gasification-coal coupling power generation is an economic means of technical innovation, which can significantly reduce the coal consumption, optimize energy structure, improve the utilization efficiency of biomass resources, reducing carbon emissions, and is also the important way for China to achieve the goal of not less than 50% of non-fossil energy power generation by 2030.