With the widely use of laser in industry, agriculture, medical and military, the requirement of its preceding excitation power supply is also getting higher and higher. In this paper, a high-voltage repetition-frequency charging power supply (HVRFCPS) used for pulsed laser is described, which use the principle of series resonant and power electronic conversion. A high-frequency high-voltage transformer and a high-voltage silicon rectifier are also used to obtain the DC voltage, which output power can reach 20kW. The control system of the power supply is based on DSP, so that the output voltage can be regulated from 0 to 30 kV, the repetition frequency can be regulated from 1 to 100 Hz by the setting of the control system. Some other functions are also designed, such as the two control modes of remote computer control by PC and local control by LCD and keyboard. In order to extend the application of this power supply, an external trigger control interface is also provided for the synchronization control of the power supply and other equipments of the pulsed laser system. In the experiment, the power supply was used as the preceding excitation power supply of the pulsed laser. Different results can be obtained by regulating the different output voltages and different repetition frequencies. The experiment results show that the power supply can work effectively.