Abstract: Non-destructive testing (NDT) refers to the detection of defects inside and on the surface of components through non-destructive means. In the field of non-destructive testing, magnetic barkhausen noise (MBN) has outstanding advantages in the assessment of stress distribution, microstructure evolution and early damage detection of ferromagnetic components due to its unique physical mechanism and microscopic sensitivity. Firstly, systematically expound the physical characteristics and detection mechanism of magnetic buckhausen noise technology. Secondly, analyze the application of magnetic buckhausen noise technology in the fields of microstructure state characterization of ferromagnetic components, stress state and microcrack detection, and deformation detection of rails and wheels. Finally, the challenges faced by magnetic bakhausen noise technology are discussed, and its future development direction and application prospects are prospected.