Abstract: Microstructure transformation of ferromagnetic material caused by stress can be detected by magnetic Barkhausen noise (MBN) technique,which was a reliable method to estimate the stress condition and failure condition of magnetic material. This paper illustrated the MBN phenomenon based on magnetic domain theory and magnetization theory, and also evaluated the influence of MBN signal caused by stress using the Jiles-Atherton magnetization model. The change characteristic of MBN signal was illustrated when the magnetic material was under the situation of elastic deformation stage and plastic deformation respectively. Moreover, the influence of loading stress and residual stress to microstructure, such as domain structure, easy magnetization axis and anisotropy, was discussed essentially. It was pointed out that the stress would not only cause defects in the magnetic material to decrease Barkhausen jump, but also cause the domain wall merger to increase the Barkhausen jump. Eventually, the final Barkhausen signal was the interaction of the decreased and increased jumps. Furthermore, the superiorities, deficiencies and new research area of MBN stress evaluation technique were summarized.