aking the surface-contact model between rigid flat punch and elastic half-space as the research subject, and through comparing the results of analytical solution and numerical simulation by the finite element method (FEM) software MSC.Marc, it is determined that the non-uniform meshing method and the third grade FEM calculation are reliable as to the surface-contact problem with definite contact area. For the most fundamental surface-contact problem involved with friction hydro pillar processing in friction stitch welding, the normal stress on the contact surface increases quadratically from center to the marginal side. The diameter of the metal stud and the applied external load has more influence to the distribution of normal stress on the contact surface, while the influence of radial clearance, the material combination between the metal stud and the predrilled hole are relatively small.