Diamond-like carbon(DLC)films are widely used in the infrared protection window,but their ability of anti-laser damage is insufficient.The common methods to improve the anti-laser ability of DLC films were summarized at first,then a new method which use the external electric field was proposed.Based on the standards ISO11254 of laser damage threshold,the damage morphology of DLC films with and without the bias field were compared.The results show that with the bias field,damage morphologies changes obviously under the same laser energy.According to the physical mechanism analysis,the photogenerated electrons of the films under the action of electric field drift speedy,the drift reduce the heat generated from the laser radiation area,then relayed the graphitization of the DLC films.This after-treated method will be a new method to improve DLC filmsanti-laser damage ability.