The invention relates to an old house reinforcing structure and a reinforcing method of the old house reinforcing structure, and belongs to the technical field of seismic hardening. The old house reinforcing structure comprises an original ring beam, an original floor and an original structure column, and further comprises newly-added channel steel, anchored bars, a newly-added rectangular steel plate, a newly-added long flat steel plate support and a steel base plate. The newly-added channel steel is arranged on the two sides of the original ring beam, drilled holes are formed in the original ring beam, the anchored bars are arranged in the drilled holes in a penetrating mode, two ends of the anchored bars are connected with the newly-added channel steel on the two sides respectively, the newly-added rectangular steel plate is arranged at the bottom of the original ring beam, and the contact portion of the newly-added steel plate and the lower edge of the newly-added channel steel is welded. The steel base plate is buried in the position, close to the original structure column, of the ground or the floor, the newly-added long flat steel plate support is welded between the steel base plate and the upper newly-added rectangular steel plate, and the newly-added long flat steel plate support is firmly bonded with the original structure column. The stability and safety of old house wall reconstruction engineering are guaranteed, and the problem that in old factory reconstruction, the original house is not reasonable in layout and poor in seismic resisting performance is solved.