The damping properties of elastic ring squeeze film damper (ERSFD) is obscure, particularly the causes and effects of elastic ring deflection. On account of the theory of fluid film lubrication, the central difference method is utilized to calculate the ERSFD dynamic properties considering contact deformation, the effects of convexities and ER deflection on the oil film pressure are analyzed, and the effect of eccentricity on the mechanical properties of ERSFD is discussed. The results show that the contact deflection reduces the maximum value of oil film pressure and makes the oil film peak sparse, and the unique factor in the generation of external oil film pressure is contact deformation.