Due to its unique properties,e:g:high melting temperature,high thermal conductivity and low sputtering erosion,tungsten(W)has been selected as one of the most promising candidate materials for the divertor in ITER and future fusion devices[1].In fusion reactors,tungsten will suffer from radiation damages by energetic particles,leading to the degradation of material properties,affecting the life time of components.Void is one of important typical radiation defects.It changes the local stress field,which influences the dislocation behaviors and the mechanical properties of materials.