The invention relates to a deformation correcting method of the circumferential weld of a thin-wall titanium alloy welding casing. According to the technical scheme, the method is implemented through a hot rolling correcting device which is composed of an upper rolling disc, a lower rolling disc, pressurizing mechanisms, a power supply and a circuit; the method comprises the following steps of pressurization, electric heating and rolling. The deformation correcting method of the circumferential weld of the thin-wall titanium alloy welding casing can effectively reduce the material strength of deformed portions, improve material plasticity and accordingly correct the deformed portions and meanwhile avoid correcting cracks, and can meet the quality requirements of repairing and remedying failure parts of the thin-wall titanium alloy welding casing of an aero-engine.