Abstract: The simulation and experimental results of electron gun with a ferroelectric material cathode by author in Cornell university are presented in this paper. The results show that the current densities is of order 110A/cm2, experimental. The current generated with the ferroelectric material cathode exceeds space charge limited current, It is considered this is caused by the electric field enhancement near the cathode surface, due to the introduction of trigger pulse, FE effect, and grid structure etc. Enhanced electric field will accelerate electrons to some energy in the district near cathode surface. According to this, The electron gun with ferroelectric material cathode can be simulated and designed by injecting electrons from cathode with an effective initial energy.