Finite element models of temperature field of permafrost asphalt airport pavement subgrade are constructed based on ABAQUS and the secondary development platform．The temperature fields of airport pavement under different widths are compared and analyzed by the model, while the influence of ground temperature field and the change rules of melting depth are studied. The results show that the width of airport pavement has a great impact on the temperature of subgrade. After the same time durition, the highest temperature of subgrade melt nuclear will keep rising constantly with the increase of width, the melt nuclear area is expanding continuously, and the central nucleus will grow fuller. The ambient temperature will influence the subgrade temperature within 5 m significantly, and the influence will be increasingly less along with the increase of the depth when the temperature of the subgrade is kept constant after reaching a certain depth. The geothermal temperature of different pavement width changes along with the horizontal changes of direction via the distribution of “Z” type, and the closer to the road shoulder, the more obvious the change. The impact area of airport pavement on natural permafrost is within 20 m from the shoulder. There are two phases of rising trend in the melting depth at the center when the width increases. The melting depth at the center is deeper than the one at the shoulder, and the width of airport pavement has little impact on the melting depth at the shoulder. Therefore, the change rule between the width of airport pavement and melting depth at the center is established base on the above statement which can provide a theoretical basis for airport construction in field of permafrost.