The tires of the aircraft are generally filled with nitrogen. Nitrogen gas which is almost inert to nitrogen, its chemical properties are extremely inactive, its molecular size is larger than that of oxygen molecules, it is not easy to expand and contract, and its deformation range is small. Its penetration into the tire sidewall is about 30-40% slower than air, and it can remain stable. The tire pressure improves the stability of the tire driving and ensures the driving comfort; the audio conductivity of nitrogen is low, which is equivalent to 1/5 of ordinary air. The use of nitrogen can effectively reduce the noise of the tire and improve the quietness of driving.