Abstract: In order to further explore the characteristics of the permanent magnet excitation device for steel wire rope nondestructive testing, a comprehensive analysis of the excitation device was carried out in order to improve the performance of the detector. The three-dimensional modeling and finite element simulation method are used to analyze the influence of the position of the permanent magnet in the permanent magnet excitation device and the excitation circuit on the excitation effect. The structure size of the excitation device for the excitation of the steel wire rope with a diameter of 36 mm is designed and used. The device excites the wire rope with a diameter of 16-36mm, and analyzes the excitation effect by equivalent magnetic circuit calculation and finite element simulation. The research results show that placing permanent magnets on both ends of the permanent magnet excitation device can form a uniform magnetization section in the middle of the excitation device, which is beneficial to the placement of the detecting components. The multi-circuit circumferentially distributed excitation magnetic circuit can make the steel wire magnetize more evenly and It is easier to magnetize the wire rope to saturation state; the permanent magnet excitation device has universal property.