Method of improving external pressure stability of thin-walled pressure vessel

The invention relates to the field of pressure vessel manufacturing, and aims at providing a method of improving the external pressure stability of a thin-walled pressure vessel. The method is characterized in that a pressure pump is used to raise internal pressure of a pressure vessel filled with water, after the pressure rises to internal pressure overpressure treatment pressure Pu, pressure maintaining is carried out for a period of time, and then pressure is relieved; with respect to an internal pressure vessel, the internal pressure overpressure treatment pressure Pu is 1.6-1.8 times of the design pressure; and with respect to an external pressure vessel, the internal pressure overpressure treatment pressure Pu is 1.6-1.8 times of calculating pressure Pc. Through internal pressure overpressure treatment on the thin-walled pressure vessel, the shape defects like the roundness of the thin-walled pressure vessel are overcome, thus the external pressure stability of the thin-walled pressure vessel is improve