Abstract：It has merits of simple，directness and concept clarity for simulation of the sliding state between pile and soil contact surface by using no thickness sliding surface element under axial load. Aiming at the axial symmetry problem of pile and soil interaction，according to basic concept of element matrix，by simplifying the thickless sliding contact surface and integral calculating to perimeter of pile，an element matrix¢s precise close solution of no thickness axial symmetry sliding surface between pile-soil contact is obtained which is fit for simulating the slide between pile and soil contact surface and to provide the theory basis for its further application. It indicates that the precise solution of element of the no thickness axial symmetry sliding surface can simulate the columnar pile and soil contact surface better，and the precise solution is easy to be adopted in the FEM numerical simulation. The surface sliding element is a special form，and it can be uniformly expressed by the axial symmetry sliding element. Consequently，it reduces the element types in the numerical simulation study of pile and soil interaction. It is significant to reduce calculating domain，work of preparing data，time of calculating and increase calculate benefit.
