Abstract: This paper is based on the design of the TMR sensor in nondestructive testing of wire ropes,and makes use of the advantages of the high sensitivity and the high signal-to-noise ratio,and tests the steel bar which is similar with the wire rope in material and structure. By using the TMR sensor in different distributions to experiment on the leakage stray field of the steel bar defects,the best measuring direction in the leakage magnetic fields and the perfect lift-off distance are determined. This paper also analyses the results of the tests,then makes use of the best way from the experiment to test the steel wire rope in different diameter and damaged levels. Finally,we verify the recognition capability of the TMR of steel wire rope and the advantages of TMR sensor in nondestructive wire rope tests,and we provide a new method of the later nondestructive wire rope tests.