The study on dislocations interacting with interface is of primary importance for analyzing the strengthening and hardening mechanisms of materials.The majority of existing research works treated the interface as perfectly bonded,i.e.the displacement and traction continuously across the interface.After 1980s,there are many research works for imperfect interfaces characterized by discontinuity of displacement across the interface.Among the various imperfect interface models,the linear spring model has been widely used to describe a soft imperfect interface across which the displacement is discontinuous.The spring model has been introduced into the research on interaction of dislocation/interface [1,2].However,the stress across interface could also have a jump,such imperfect interface is called stiff imperfect interface.