Abstract: A 22 stage 5 MV laser-triggered multi-stage switch was designed based on the principle of laser-produced plasma and over-voltage wave. A metal ring was connected to a voltage divider to form a voltage-holding ring which was used to solve the problem of field regularity in small space. The relative difference of the electronic field of the selfbreakdown gaps was less than 0.056 and the relative error of the electronic field of the laser-triggered gap was less than 0.080 in the voltage-holding ring scheme. The switch and switch container were designed based on the results of electrostatic calculation. The satety factor of the switch and its' container was 0.8. The breakdown electronic field was calculated by J.C.Martin formula.