The invention relates to a large-scale biomass power generation process which comprises the following steps: after being stacked in a storage yard, a biomass is added in a biomass gasification furnaceby charging equipment through processing treatment; the biggest characteristic of the furnace is that a combustion chamber for providing heat and a gasification tank are relatively-independent spaces, and the heat in the combustion chamber is transferred to the gasification tank through a partition wall. After the pyrolysis and the gasification of the biomass are finished in the gasification tank, gas enters the combustion chamber for combustion, generated high-temperature flue gas is produced into steam through a waste heat boiler, and the steam drives a steam turbine to generate power. Compared with an existing biomass power generation process, the large-scale biomass power generation process provided by the invention has the significant advantages of being wide in raw material adaptability, large in handling capacity, high in environmental protection, low in investment, low in cost and the like.