Abstract: Pseudospark switch is a kind of pulse power switch with high voltage and high current. High Pulse Repetition Frequency（PRF） pseudospark switch has been widely used in underwater communication, underwater countermeasures, high energy laser weapons, sewage treatment, food processing and other fields. The choice of cathode material is related to the on-off process of the switch, so it has an important influence on the PRF performance. The trigger unit is simulated and analyzed, and the influence of electrode material for both LaB₆ and Cu on the cathode emission current and internal electron density is obtained and compared. The pseudospark switch of LaB₆ and Cu cathodes is tested. The results show that LaB₆ cathode has a wide range of working pressure, the minimum trigger voltage can be only 100 V, and the operation stability is quite well.