The polarity effect exists in the electrical explosion of wires（EEW） in vacuum. Changing the direction and value of the radial electric field can change the deposition energy of EEW. Consequently

we adopted an insulated cathode（cathode with an embedded insulator） to improve the distribution of surface radial electric field of parallel double-wire load. In order to verify the effectiveness of this method to improve the deposition energy of EEW

we carried out simulation of electrostatic field under two types of electrodes（an insulated cathode and a normal cathode）. Simulation results show that the insulated cathode can effectively improve the distribution of radial electric field on the surface of parallel wires: changing the negative direction of radial electric field into positive direction

thus suppressing the electron emission of wire surface. The experimental results based on a PPG–3 device further verify the conclusion that the insulated cathode can significantly improve the deposition energy in wires（from 3.2 eV to 12.5 eV） and result in a better electric explosion effect with a faster expansion rate（from 1.23 eV to 3.95 eV） and higher vaporization ratio.