Abstract: In this paper,the design and experimental results of 3MV operating-voltage peaking capacitor MWF-3000-55 are described.A new design method by uniforming voltage distribution along the capacitor surfacr is adopted to design MWF-3000-55 peaking capacitor.The designed capacitor is characterized by high operating voltage, small size and light weight.The MWF-3000-55 peaking capacitors have passed the test of 3MW pulse voltage and been successfully used in a 2MV electromagnetic pulse generator.