Abstract: In order to further understand the stray interference phenomenon of the steel wire rope in nondestructive testing, the electromagnetic detection technology was studied in order to improve the accuracy and reliability of the test.In combination with the working process and principle of wire rope nondestructive flaw detector to detect from the aspects of rope's structure and the working condition, the factors of the clutter of the electromagnetic detection signal are presented,and by using Ansys simulation to analyze the leakage magnetic properties of the wire rope when the non-destructive flaw detector was used to excite the steel wire rope for further verification.Research results show that:The interleaved air gap produced by the spiral structure of the wire rope,The diameter difference between the non-destructive flaw detector and the measured wire rope and the vibration during the operation of wire rope which is the important factor that the wire rope is detected in the signal,and it may have a great influence on the electromagnetic detection signal of wire rope even causes a misjudgment of the detection signal.