A kind of detection sensor is designed for ferromagnetic materials to obtain Barkhausen noise signal.Through the finite element electromagnetic simulation software Ansoft, the common H-type and U-type excitation modules are simulated and analyzed, and the magnetization effect of specific test pieces is analyzed. According to the magnetization effect and manufacturing difficulty, the H-type yoke is selected as the excitation module finally. Theoretical calculation and experimental phenomena are combined to analyze the factors that affect the performance of the Magnetic Barkhausen noise signal detection sensor. It is concluded that the magnetic field will attenuate when it propagates perpendicular to the surface of the material and is inversely proportional to the frequency of the coil excitation signal. The adjustment of the magnetization depth can be realized by adjusting the frequency of the signal, and the amplitude of the signal will affect the magnetization strength of the test piece; the flexibility of the receiving coil The sensitivity is directly proportional to the length and diameter of the core and the number of turns of the winding coil, but the distributed capacitance, effective resistance of the winding coil and the size of the receiving coil should also be considered. Finally, the designed sensor can obtain the Magnetic Barkhausen noise signal with better signal-to-noise ratio.