Abstract: In order to study the damage law of carbon fiber reinforcement plastic (CFRP) caused by lightning current, direct effect experiment of lightning current and electrical-thermal coupled effect simulation for CFRP were carried out. At first, direct effect experiment of lightning current was implemented with the impulse current experiment apparatus. External damages subjected to currents with different peak-values were compared together, and internal damages were observed with C-scan. Experiment results show that damage range increases obviously with the increasing peak value of current, and the range of internal damage is much larger than that of the external damage. Then, electrical-thermal coupled finite element analysis of specimen was carried out, and the superimposed temperature field was approximately chosen to represent the range of internal damage. The comparison with the experiment results shows the effectiveness of this method. The results of thermal-electrical coupled analysis under impact currents with different types and action integrals show that the range of damage is greatly influenced by action integral.