According to the working characteristics of He-Ne laser DC high voltage, a He-Ne laser power supply is successfully designed. The He-Ne laser power supply is based on the PWM control chip SG3524, and adopts a constant frequency pulse width modulation control mode to automatically adjust the output power to obtain a stable power output. The flyback transformer driver circuit is reasonable designed. The effective control of the power supply current and the self-stabilization of the current during operation are realized. The current stability of the laser power source and the laser light power stability are tested at current values of 3, 4 and 5 mA. The test results show that the laser power output current and the laser output power are both stable. The power supply has the advantages of simple structure, high efficiency and stability, small size , light weight , which has strong promotion.