Carbon/epoxy (C/E) composites have been widely used in aerospace and automotive industry. However, they are prone to appear damages such as burr, spalling, delamination during drilling process. This paper presents an electroplated diamond abrasive drilling (EDAD) technology to reduce these damages. With this technology, C/E composites are removed by the action of the motion of small diamond particles attached to a core drill body. In order to represent the drilling damages, a new evaluation method is proposed taking comprehensive consideration of burr, spalling and delamination. The method is verified by analyzing the damages of drilled holes. Results indicate that the evaluation method proposed in this paper is applicable to characterize the level of drilling damages reasonably and effectively.