The open innovation model, which refers to the use of external technology and the environment, has boosted the technology developing speed to a large extent. The term open innovation was launched by Chesbrough. In the open innovation model, firms utilize a wide range of both internal and external sources and channels to commercialize their ideas. The technology market is complicated. Therefore, open innovation is not a single, unique strategy. There are many different moves and approaches that can all lead to a firm's success in innovation competition. Previous studies in this field were usually done in a qualitative way. In this paper, we are aiming to study the open innovation approach with a qualitative method, data envelopment analysis (DEA). Eighteen companies, which are recognized as pioneers in open innovation, have been selected in this study of R&D efficiency evaluation and open innovation strategy discussion. Since R&D efficiency is always a key part of the innovation process, the objective of this paper is to analyze how a company's choice of an open innovation strategy model will influence its R&D efficiency DEA ranking, and how its R&D efficiency at different stages can be aligned with its open innovation strategy.