New and old building connection method for urban reconstruction and waterproof construction auxiliary device

The invention discloses a new and old building connecting method and a waterproof construction auxiliary device for urban renovation, and particularly relates to the technical field of urban renovation. An eccentric distance is not generated between forces in two different directions by vertically aligning the positions of support piles below a newly-built structure outer wall and a foundation bottom plate; the bottom plate is prevented from being damaged due to non-uniform stress generated by the bottom plate and the basement outer wall, a waterproof additional layer is additionally arranged at a joint, and a water stop steel plate is arranged at a construction joint, so that the waterproof requirement of the structure connecting part is ensured, the phenomenon of water seepage is avoided, and the forming quality of the underground structure of the deep foundation pit engineering is greatly improved; according to the method, the waterproof effect of the underground structure connecting section is improved, t