Abstract: China has been undergoing the phase of rapid city construction for nearly thirty years, in which the city appearance has improved considerably. The massive city construction has come to an end. Megacities, represented by Shanghai, have ascended to the era of stock from the era of increment. How to renovate and update the common buildings that deserve preservation but are not cultural heritages in order to make them both inherit historical traces and adapt to the current using function, and enhance the regional functions, environmental quality and local culture of existing buildings to bring a new life experience to people's lives and save construction costs is the major issue of city construction renewal at present. Two old construction renewal projects of Shanghai Ba Fen Yuan Art Museum and Tongji Architectural Design and Research Institute were taken as examples to analyze the realization of the personalized upgrade and sustainable development of city old buildings by means of reasonable renewal and industrial transformation in the practical activities of analyzing the reuse of old buildings.