The present invention discloses a characterization method for aging of cross-linked polyethylene insulation materials for submarine cables. The method comprises following steps: a) respectively performing mechanical, chemical, thermal and electrical performance tests on the cross-linked polyethylene insulation materials of different aging degrees, and obtaining a changing rule of each characteristic parameter along with the aging degree; and further dividing aging intervals, and establishing a reference sequence according to characteristic parameters corresponding to threshold points of different stages in the aging intervals; b) performing the same performance test as the step a) on the cross-linked polyethylene insulating materials at an unknown aging state, and establishing a to-be-matched sequence through using obtained characteristic parameters; and c) calculating correlation degree between the to-be-matched sequence established in the step b) and the reference sequence established in the step a), matching the aging intervals, and determining the aging degree of the materials. The characterization method combines multiple characteristic parameters of physical and chemical properties, combines with more scientific aging interval division and more accurate correlation calculation, and can comprehensively and accurately reflect aging state of the materials.