IntroductionBarkhausen effect was found for the fist time in 1919, after years of research, today it developed into a nondestructive testing technology. The nondestructive testing technology based on Barkhausen effect is using the presence of magnetic signal caused by the exceptions or defects of the internal structure of materials to determine the damage degree of abnormalities and defects of the structure. It being mainly used for evaluating the quality and fatigue condition of the ferromagnetic materials, having the advantages of nondestructive, quantitative, reliable, fast, through the electric plating layer, large area detected, environmental protection and no harm to human body, the technology has significant application value in fields that including machinery, metallurgy, construction, aviation and aerospace, nuclear energy, transportation and other industries, as well as the geological exploration, safety testing, materials science and so on. Thus, the nondestructive testing technology based on the Barkhausen effect has become hot spot of the research.