Abstract: A control system based on DSP is designed for the application of the power supply. By regulating the control system, the output voltage can be regulated from 0 to 30 kV, and the repetition frequency can be regulated from 1 to 100 Hz. In order to operate more easily, two control modes are designed, one is the remote computer control and the other is the local control by LCD and keyboard. The multiple protective circuits are designed to process the faults which are over voltage, over current, over time or over temperature. In order to extend the application of this power supply, an external trigger control interface is provided for the synchronization control of the power supply and other equipments of the laser. The electromagnetic compatibility design of the power supply is adopted in the control system. Coupled with a fiber optical control and feed back communication system, the anti-interference performance of the control system is much better.