Abstract: Due to the poor conductivity, carbon fiber reinforced resin matrix composites (CFRP) cannot meet the lightning strike protection requirement of aircrafts. The metallization of carbon nanotube (CNT) films are lightweight, and possess high conductivity and high current-carrying capacity, making them promising for lightning strike protection of composite materials. CNT/Cu composite films were successfully prepared by electrochemical deposition process, and its microstructure, electrical properties and current-carrying failure behavior were characterized and analyzed. The results show that CNT/Cu composite films are flexible and have gradient microstructures, where the content of Cu gradually decreases from one side to another. The electrical conductivity of the composite films is 2.16×10⁷ S/m, and their specific conductivity is 2 times of pure Cu, and the current carrying capacity and specific current carrying capacity are 1.4 times and 7 times of copper mesh, respectively. CNTs in the composite film can inhibit the electromigration of Cu, thus prolonging its current-carrying failure time. CFRPs for lightning strike protection testing were prepared by using CNT/Cu composite films, and the lightning strike protection performance was evaluated by artificial simulation lightning test and damage analysis. Compared with copper mesh, CNT/Cu composite films are 61% lighter and showed more excellent lightning protection performance.