A biomass fuel burner (1) comprising an outer cylinder (10) and an inner cylinder (20) accommodated within the outer cylinder (10). The inner cylinder (20) is provided with an inner cylinder bottom face (21) and an inner cylinder lateral face (22). Several primary air supply holes (24) are evenly provided on the inner cylinder bottom face (21) of the inner cylinder (20); a row of secondary air supply holes (25) consisting of several single holes is provided on the inner cylinder lateral face (22) of the inner cylinder (20) in proximity to an inner cylinder upper edge (23). An air supply tube (40) in communication with the outer cylinder (10) is provided on the outer cylinder (10). The ratio between the total area of all of the secondary air supply holes (25) and the total area of all of the primary air supply holes (24) is 1:1.1 to 1.2. The burner (1) increases the efficiency of combustion and the quality of energy conversion.
