Abstract: The THz device is a new type of microwave device which operates in the 0.1-10 THz frequency band, and it has important application value in the field of communication, imaging, detection and other military applications. Compared with the traditional vacuum microwave devices, the THz device has the characteristics of light load and high duty cycle. A high frequency pulsed power supply system has been developed for the experimental research on THz devices. The output voltage is 30 kV, the pulse current is 200 mA, the maximum frequency is 3 kHz and the pulse width is 10-100 μs. The main circuit adopts LC series resonant constant current charging technology to improve the reliability in the case of fire load. At the same time, a series pulse switch based on MOSFETs is developed to obtain fast pulse rise and fall time. A PLC and a computer have been used to realize the local and remote control. Relevant simulation and test show that the system output meets the load requirements, and the system can work stably in high frequency, load arc conditions.