On the base of the dynamic detection on the cavity wall in the large rural areas of South China,the different conditions of the cavity wall finite element model for masonry structures were established.The qualitative structural response was judged by the modal response analysis,and the seismic performance was researched by the response spectrum analysis.The results show that the average shear stress suffered by the empty bucket is 55% of solid walls with the same size under the same intensity.The door and window openings,the vertical and horizontal transfer of the wall,the floor and wall overlap and the projecting stairwell are the weak parts of empty bucket against the earthquake,while the traditional structural measures,such as,beam,pillar,are useful to improve the seismic performance though the cavity wall structure is complicated.