Abstract: Electron accelerators adjust electromagnetic field to guide the electron beam to travel along an ideal orbit, requiring reliable excitation power supply with high precision, high reliability, small ripple and strong anti-interference ability. This paper introduces the structure, controller system and control algorithm of NSRL-HLS low power DC magnet power supply, as well as some relative simulation and experiment research. The measured current ripple is 2.12, the current stability is 6.6 and the current resolution is 0.01 under the load inductance 1.0 mH, equivalent series resistance 0.049 and output current 25 A. It is proved that the designed main circuit and controller system are suitable for the experimental research of low power DC magnet power supply.