This paper mainly studies the traffic discharge conversion on asphalt pavement and presents that the property of main landing gear can be known by the load circle radius, tire pressure, wheel-tread and radius ratio, distance between tandem and radius ratio. Characteristics of wheel-tread and radius ratio, distance between tandem and radius ratio on current airplane are analyzed based on probability theory. Wheel-tread and radius ratio of typical dual wheel gear is 3.32, the dual tandem dual wheel gear is classified into three models by distance between tandem and radius ratio 6.791 and the wheel-tread and radius ratios 4.0 and 5.0. By applying the fatigue principle and the conversion standard of tensile stress of the bottom of sub-base and the fatigue equation as the conversion standards, selecting 7kinds of typical construction to calculate the greatest tensile stress of the bottom of sub-base for the iso-type gear and hetero-type gear of different the load circle radius and tire pressure, the conversion coefficient of the gear is obtained and the traffic discharge conversion relation between the design airplane and other airplanes is established. The traffic discharge conversion satisfies the principle that the asphalt pavements designed according to the different design airplanes are equal in thicknesses.