The building of the formerly Yihe Spinner Factory in Shanghai is a protected. To ensure its serviceability, appropriate retrofitting is necessary. Structural analysis based on the inspection result was performed. It is shown that the bearing capacity or the ductility of some members in the original structure as well as the retrofit proposal are inadequate. Strengthening design was then performed. The effect of the subsequent retrofitting process on the strengthened structure was analyzed. The historical building is then properly protected and the new manufacturing requirements are meet through the retrofitting and strengthening design. The proposed methods can serve as references for relative research or engineering practices.