The invention discloses a biomass burner which comprises a burning chamber, a hopper above the burning chamber, a safety valve beside the hopper, a grate at the lower part of the burning chamber, an ash storage cavity below the grate, an ash exhaust hole connected with the ash storage cavity, a heat-insulation housing at the periphery of the burning chamber, a control panel outside the heat-insulation housing, a fan outside the burning chamber, a fire box connected with the burning chamber, a cyclone dust collector on the fire box, a fire outlet at the tail end of the fire box, and a reinforcing rib connecting the fire box and the heat-insulation housing. The biomass burner is simple in structure, is easy to install and is capable of effectively filtering dust in flames of the fire outlet, and the burning efficiency is improved.