Sewage treatment system reconstruction method

The invention relates to the field of environmental protection engineering construction, and provides a sewage treatment system reconstruction method. The method adopts an MBR reaction tank as a transition device for treating sewage in the sewage treatment system reconstruction process. Compared with a conventional biological reaction tank, the MBR reaction tank has the advantages of small occupied area and high sewage treatment capacity, and can be built by only utilizing a small part of the occupied area beside the existing sewage treatment device. Sewage treatment in the reconstruction process is completed by utilizing the MBR reaction tank, so normal sewage treatment is not affected when the existing sewage treatment device is dismounted, disassembling of the sewage treatment device for many times is avoided, and the reconstruction period can be shortened; and after the MBR reaction tank is reconstructed, MBR parts in the MBR reaction tank can be disassembled, and the tank body ofthe MBR reaction tank can