The invention relates to a multi-channel dense-thin separation type single cone burner and a using method thereof. The burner comprises a pulverized coal supply mechanism, a transition channel, a multi-stage air assembly, at least one deflector, a combustion stabilizing chamber and a rectifying chamber, wherein the multi-stage air assembly comprises N air ducts, the Nth air duct is connected withthe combustion stabilizing chamber and the rectifying chamber sequentially, the pulverized coal supply mechanism comprises an air and pulverized coal pipe and a reach-lean separator, the air and pulverized coal pipe communicates with the combustion stabilizing chamber, the reach-lean separator is detachably connected to the air and pulverized coal pipe, and the transition channel is arranged at aninterval in the first air duct; each air duct is of a double-layer hollow structure, and one end of at least one deflector is inserted into the corresponding air duct; and at least one direct flow channel is formed between each deflector and the combustion stabilizing chamber, a flare is formed at the other end of each deflector, and the angle of each flare is the same as that of the combustion stabilizing chamber. Air can be divided into N strands to enter a burner body, turbulence intensity at the airflow boundary is high, the mixing speed of air and pulverized coal is increased, the pulverized coal is stably ignited, and high-efficiency and low-nitrogen burning of the pulverized coal can also be ensured.