Abstract: To realize the portable non-destructive testing instrument based on Magnetic Barkhausen Noise, the MBN signal sensing module and conditioning module is designed and put into use.Taking advantage of the high-performance digital signal processor served as the core component in the system, the equipment achieves four functions as follows:generating excitation signals, collecting MBN signals, processing and storing experiment data and controlling the LCD screen.In addition, the system is served for the irradiation embrittlement detection of Reactor Pressure Vessel steel samples based on MBN signals. As the experiment shows, the instrument based on DSP performs with higher detection accuracy and faster processing speed. It lays a good foundation for nondestructive detection based on Barkhausen noise.