A nondestructive testing method for detecting and distinguishing internal and external defects of a wire rope includes: acquiring a magnetic flux signal and a MFL signal of a detected wire rope; preprocessing the magnetic flux signal and the MFL signal of the detected wire rope; comparing a preprocessed magnetic flux signal and a preprocessed MFL signal with a preset magnetic flux signal threshold and a preset MFL signal threshold respectively, and calculating a defect position; extracting a magnetic flux signal of a defect and an MFL signal of the defect based on the defect position; calculating a defect width of the detected wire rope based on the magnetic flux signal of the defect and the MFL signal of the defect; calculating a defect cross-sectional area loss of the detected wire rope based on the defect width; and determining whether the defect is the internal defect or the external defect.