Different plastic deformation under the condition of friction coupling on a selfdeveloped friction tester was obtained by setting the reduction of punch and load. The friction tester can simulate the relative sliding under the forming force in the process of practical stamping. The surface roughness, friction coefficient and dynamic evolution were studied and analyzed to determine galling initiation. The results show that the galling initiation would go through three stages of film cracking, transfer and agglomerate, and the galling initiated earlier as the plastic deformation was larger. The surface damage was resulted from the effect of adhesive wear and plowing.