A modal pushover analysis (MPA) method based on the soil-structure interaction（SSI） was proposed through the principle of periodic equivalence, and the feasibility of this method was verified. Taking a 10-story RC frame structure with vertical irregular filling walls as the research object, we adjust the stiffness ratio between stories and the layout position of “weak stories”，and use this method to analyze the seismic response regular pattern of this kind of structure under the condition of different sites and seismic precautionary intensity. The results indicate that: 1）In strong earthquakes, setting up “weak layer” in “the most sensitive layer of weak layer” makes the effect of weak layer more significant, and the greater the ratio of stiffness between layers，the more adverse the displacement angle between layers of RC frame structure. Irregular arrangement of filled walls in the outer floor of "sensitive area of weak layer" makes the structure form the distinct weak layer. 2）With regard to SSI effect, the deformation of RC frame structure with filled wall concentrates more obviously to the bottom floor, and the stiffness ratio between layers decreases when the structure collapses and the site soil becomes soft. Therefore，it is proposed to control the stiffness ratio between stories more strictly to ensure the ductility of such structures under earthquake effect.