A sealed plasma electrode pockels cell (PEPC) has been developed for use on the petawatt and exawatt class laser system that can be used in high-contrast optical switch, as required for suppression of self-oscillation, isolation from retroreflected pulses, and control of output beams. The initial concentration of Ne in the discharge cell is more than 99.9%, which prevents the discharge electrodes from reacting with O₂ comparing with unsealed PEPC. The theoretical lifetime of the sealed PEPC is more than 40 years as the leak rate of the sealed PEPC is smaller than 1.0×10^-10 Pa∙m³∙s^-1. The experimental results show that, the discharge electrodes in the sealed PEPC are still as fresh as new after firing 200,000 times and the time jitter is still below 6.4 ns.