The multi-grid composite wall-shear wall structure (the hybrid structure discussed in this paper) is a new dual structural system consisting of the multi-grid composite walls and the RC shear walls. Because of the shear deformation of the composite walls subject to arbitrary loads, it is not accurate to calculate the horizontal displacement of the hybrid structure by using the displacement formulations of the frame-shear wall structure. And therefore, a displacement calculation method for the hybrid structure subjected to horizontal loads should be proposed. In this paper, the composite walls are viewed as shear-flexural type cantilever walls and the shear walls as flexural type cantilever walls. Based on the Timoshenko beam theory, the displacement differential equation of the hybrid structure is proposed by the continuum method. The analytical solutions of the displacement equation for the hybrid structure subject to the inverse triangle load are obtained with boundary conditions. The example indicates that the lateral displacement curve of the hybrid structure from the proposed method exhibits a shear-flexural type characteristic in which the shear deformation should not be ignored.