The work aims to propose a modular division method for product sustainable design to realize rapid development of sustainable products. The product functions were disassembled and the product function structure was established based on the function chain model. The qualitative division of function modules of the products was achieved based on the forms and the relations of function chain. On this basis, the quantitative division of modules was achieved by the clustering analysis according to the relativity judgment of parameter flow. The sustainable design principles and features of the product life cycle were integrated, and the modular division of sustainable design was conducted based on the component relevancy of design structure matrix. Combined with the two results of module division, the module was combined, replaced and redivided from the perspective of sustainable design, so as to achieve the best module division solution. The product module obtained in the proposed method has sustainability on the basis of satisfying the functions and realizes the sustainable design of products. This method integrating the function and the whole life cycle has achieved the modular division of products based on the sustainability.