The actual distribution of axle load of main pavements was measured using the movable axle load meter to analyze the extent of overloading, some relative finite element programs were compiled to study the effect of vehicle load on asphalt pavement through changing vehicle load, and the effect of asymmetric load on pavement performances. The results show that the heavy load and overloading vehicles extensively exist throughout China, and tyre pressure is usually over 0.7 MPa, shear stress of surface, stress of base and subbase and pressure stress of subgrade are increasing up when the axle load increases, which indicates that overloading is a main factor of the early destruction of asphalt pavement.