Abstract: A method was proposed for the needs of automatic NDT of non-ferromagnetic material, which measured the magnetic field induced by DC current flow with integrated hall elements. The hall elements detected the variation of magnetic field in the air near the surface of the material non-contactly, and then the signals were processed to obtain the information of the flaws. The experiment analyzed the principle of the method and studied the influence factors to the measured signals, which were the excitation current density, the depth and location of the cracks. The result showed that the method, which had the similar characteristics to the magnetic flux leakage testing method, could detect the flaw not only on the surface, but also in the material. Therefore, the application of the method was significant respect in automatic and rapid testing in future.