Charge accumulation effect on the surface of the insulation film degrades the quality of the films in the process of IBAD. A square wave AC voltage power is connected to the extraction grid of the broad beam cold cathode ion source. Therefore, the positive and negative charges are neutralized to eliminate the discharge phenomenon on the surface of the film by extracting the electrons and ions out. The parameters, such as the initial energy, densities and radiation angle of the electron beam were tested in the experiment. The experiment results show that the average electronic energy is about 100eV and the emission angle of the extracted electron beam reaches ±40° when the extraction voltage is 600V. With the same parameters, the beam flux of the extracted electron beam is less then the ion beam. A good neutralization effect can be obtained by adjusting the duty cycle of the pulse power.