Abstract: The paper presents a design of high voltage pulse generator based on metal oxide semiconductor field-effect transistor (MOSFET).The high voltage and high repetition rate switch module by stacking many MOSFET in series was investigated to generate high voltage pulse. A pulse generator was designed by the switch module. An experiment setup stacking 15 MOSFETs whose V_ds is 1 kV was set up in series. A high voltage pulse with amplitude of 10 kV on 500 Ω load, duration of about 100 ns and repeat frequency of 400 kHz was obtained. Because of the fine characteristic of compact-structure and high reliability, the high voltage switch module could be used in many type of pulse generator.