The invention discloses a corrosion method for an ultra-high-voltage and high-specific-capacity positive electrode corrosion foil. The ultra-high-voltage positive electrode corrosion foil is a positive electrode foil used for an aluminium electrolytic capacitor, wherein Vt of the positive electrode foil is greater than or equal to 1,050V; and the corrosion method comprises the following steps of pre-treatment, first-stage corrosion, second-stage corrosion, third-stage corrosion and post-treatment. Through improvement of a corrosion process, corrosion mixed solution prescription and the like, the produced aluminum foil can satisfy the ultra-high-voltage formation requirement with Vt which is greater than or equal to 1,050V; in addition, the shortcoming of low specific capacity caused by high probability of blocking after formation due to small corrosion foil hole in the prior art is also overcome; higher mechanical strength and longer service life are achieved under the premise of obtaining higher pore diameter and static specific capacity; and meanwhile, the produced formation foil is high in stability, low in electric leakage, quick in voltage boosting time, and capable of filling up the blank in the field of the ultra-high-voltage corrosion foil in the prior art.