Gas burner

The utility model discloses a gas burner. The gas burner comprises an air box, an igniter, a flame observation cylinder, a flame monitor and a junction box, wherein a low-fire gas inlet is formed in the air box and is connected with a low-fire gas nozzle; a primary air cyclone is arranged on the outer side of the low-fire gas nozzle; a high-fire gas inlet is formed in the air box and is connected with a high-fire gas nozzle; a secondary air cyclone is arranged on the outer side of the high-fire gas nozzle; the low-fire gas nozzle and the high-fire gas nozzle are of a concentric structure; the low-fire gas nozzle is connected with primary combustion-supporting air; the high-fire gas nozzle is connected with secondary combustion-supporting air. By virtue of the arranged low-fire gas nozzle, the regulation ratio and the regulation accuracy of the burner are greatly improved, and the baking oven gas requirement of a gas furnace can be met; the gas burner has the characteristics that a combustion flame is yellow bright, and the radiation heat transfer effect is good; the phenomena of tempering and lifting are avoided; the gas burner is applied to natural gas, liquefied petroleum gas, coke oven gas, biomass gas, petroleum gas, chemical tail gas and the like of which the combustion heat value is not smaller than 3,000kcal/m (standard).