The eco-composite wall structure is a new structural system, characterized by ecology, low weight, high strength, saving energy and good aseismic performance. As the main load-bearing member of the structure, Multi-ribbed composite wall consists of concealed frame, concrete frame grids, ecological filling blocks and so on, which makes the entities calculation model extremely complicated. Therefore, it is necessary to present the simplified calculation model of the structure. Based on constitution and mechanical analysis of the multi-ribbed composite wall, the wall is equaled to an elastic plate with the filling blocks as matrix and concrete grids as reinforced fibers in elastic stage, consequentially rigid frame-composite elastic plate of eco-composite wall structure is proposed, and the model is employed to perform the time-history analysis. Experimental analysis shows that rigid frame-composite elastic plate model can meet the usage of engineering in elastic stage, and it provides a more simplified calculation method.