Abstract: In recent years, the reconstruction of old city has become an important work for the further development of the city. How to transform the existing structure without causing damage to the surrounding buildings (structures) is a key concern of the industry. Combined with the reconstruction project of heavy industry workshop of Shanghai Pengpu machinery factory and according to the actual engineering situation, this paper mainly expounds the active reinforcement measures for the reserved workshop of heavy industry workshop before the construction of adjacent deep foundation pit structure, including: the original independent foundation should be strengthened by the static pressure pile, Anchor static pile foundation reinforcement, Reinforcement of broken concrete. Which effectively guarantee the deformation control and structural safety, providing reference and reference for the reconstruction of similar existing structures.