Self-balancing device and method for lifting existing building on single side of existing building structure

The invention discloses a self-balancing device and method for lifting an existing building on the single side of an existing building structure. According to the self-balancing device, a steel pull rod is tensioned through a jack to drive a self-balancing device body of a lifting steel column connected with the interior of a supporting steel column in a sleeved mode to lift the existing building. The building can be lifted to the designed height at a time without being limited by the weight of the upper structure of the lifted building and an operation site, and the defects of the site needed when lifting devices need to be symmetrically arranged on the two sides in a traditional method and the hidden danger that the structure is prone to horizontal displacement are overcome. The device is reasonable in structural design, high in automation degree and high in lifting precision, can be widely applied to existing building lifting transformation projects, is particularly suitable for specific projects limited b