The invention provides a biomass direct combustion device by combining flue gas recirculation and SNCR (selective non-catalytic reduction). The biomass direct combustion device comprises a biomass boiler, a boiler internal air distribution and denitrifying system, a residual heat boiler and a flue gas purifying system, wherein the boiler internal air distribution and denitrifying system comprises a primary air system, a secondary air and over-fire air system, a flue gas recirculation system and an SNCR system; the primary air system is used for producing primary air which is sent into the biomass boiler, and the secondary air and over-fire air system is used for producing secondary air and over-fire air which are sent into the biomass boiler; the flue gas recirculation system is used for respectively mixing the recirculated flue gas and the secondary air as well as the over-fire air; a reductant provided by the SNCR system is sent into the biomass boiler via the over-fire air. The biomass direct combustion device has the advantage that the SNCR system uses urea as a denitration reductant, so that the higher denitrifying efficiency and lower running cost are realized.