Abstract: Based on the three-dimensional magnetic sensor,the variation characteristics of three-dimensional self-emitting magnetic signals of FV520B steel were studied under different tensile loads,and different characteristic parameters of magnetic signals were analyzed and the correlations between parameters and applied stress were explored.The results indicated that three-dimensional magnetic memory signals showed different variation features during tensile process and fracturing,and could accurately locate the site of failure according to the signal changes.Meanwhile,there was a certain correlation between the parameters and applied stress,the relationship between applied stress and parameters of Bxave and KBz was approximately linear and the applied stress of the specimens could be predicted based on the eigenvalues.The elastic and plastic deformation stages could be distinguished according to the relationship between stress and parameters of KBz and Byave.Three-dimensional magnetic memory technology would provide guidance on how to identifythe damage of complex components.