In power transmission and transformation, the connection of overhead wires is realized by crimping the power fittings. The bending degree of the crimping cables is one of the important parameters for measuring the quality of the crimping. According to the characteristics of the crimping cable, an automatic measurement method based on image processing is proposed. The crimping area of the crimping cable is automatically determined by the gray-scale jump of the crimped image, the Harris corner point is detected, and the fitting point is determined by combining the gray-scale features of the image, and the curved shape of the crimping cable is fitted by the quadratic curve. The approximation is performed to calculate the bending degree of the crimp cable. The experimental results of actual crimping cable show that the method can perform rapid and automatic measurement of bending degree and can adapt to different light intensity, which can effectively eliminate the influence of the burr points on measurement result, and meet measurement accuracy requirement of the crimping process specification.