Abstract: COMSOL Multiphysics numerical simulation software was adopted to simulate the lightning attachment point and lightning current damage of a lightning protection system of carbon fiber cap spar blades. The initial pilot attachment test and arc injection test for the carbon fiber blades with lightning protection system were carried out. The simulation and test results show that lightning current mainly propagates via copper mesh, the current is distributed unevenly in the folded copper mesh. The current density in thick copper mesh is larger than that in thin copper mesh, and the current density near the injection point is larger. When lightning arc is introduced, slight corrosion will occur in copper network, and carbon fiber cap spar will not be damaged by the heat. The test results are coherent with the simulation results, which further verifies the validity and correctness of simulation.