The concept of eco-design in product design has been developed for several years. In this study, we proposed a new reasoning model to obtain innovative ideas more easily for designing eco products, which was followed by evaluating whether the proposed design here was more effective than currently available ones. The innovative solution to solving design problems was based on TRIZ evolution patterns. The index system of case-based reasoning then connected the innovative idea to cases located in a database, realizing the promising idea. Finally, simple life cycle assessment was utilized to determine the feasibility of this solution in comparison with the current ones. Meanwhile, an eco-innovative example was also applied to demonstrate the utility of the proposed model.