Abstract: A novel pulsed power supply with high energy efficiency using multiple capacitor banks discharging sequentially is investigated to generate the demanded pulsed current (flattop time 1-10 ms, minimum 24 kA) for the pulsed magnetic window technology. The electrical topology is designed and the relationships of power supply parameters, discharging branches and current ripples as well as their sensitivities to the variation of circuit loop parameters are analyzed. An optimized structure of six discharging branches is proposed and validated by the experiments. The turn-off reliability of the main discharging switches are improved by making them in series. The ability to endure the reverse voltage of crowbar diode when turning off is enhanced by a crowbar module consisting of two branches in parallel with three tandem diodes in each branch.