The burner adopts fuel classification, flue gas circulation and other technologies. The multi-layer spray gun design of the burner and the oxygen enriched combustion of the combustion supporting air are mixed in layers to form a low-temperature flame environment and reduce NOx generation. A negative pressure field is formed around the rapid combustion nozzle, bringing in an appropriate amount of flue gas to reduce the concentration of oxygen in the combustion supporting air and further inhibit the generation of NOx.