Biomass fuel preparation system

The invention discloses a biomass fuel preparation system. A space inside a furnace body is separated into a gasification reaction region and a feeding and exhausting integrated region by virtue of a first sieve plate, wherein the feeding and exhausting integrated region is separated into a biomass feeding channel and a fuel collecting and discharging channel by virtue of a barrel. A wind housing is arranged outside the feeding and exhausting integrated region along the outer wall of the furnace body in a surrounding manner and used for recycling furnace wall heat of the feeding and exhausting integrated region so as to prepare hot air. A cold air inlet is formed in the upper part of the wind housing, a hot air outlet is formed in the lower part of the wind housing, the cold air inlet is connected to a fan by virtue of a pipeline, and the hot air outlet is communicated with a hot air inlet in the bottom wall of the furnace body. Therefore, cold air is conveyed into the furnace body via the hot air inlet after being preheated into hot air in the wind housing, and the hot air and water vapor conveyed through a water vapor inlet are used for together gasifying a biomass fuel accumulated in the gasification reaction region.