It is significant to improve the simulation accuracy by improving the loading method to reduce the error between the numerical simulation and the test results. The ablation damage characteristics of composite laminates under different forms of lightning current were explored, the Braginskii arc radius expansion formula was improved, and a numerical model of arc expansion radius suitable for lightning strike process was established. A finite element model of CFRP laminate was established based on ABAQUS and the ablation damage under different current loading modes was analyzed. The results show that the finite element model can simulate the lightning strike ablation damage of CFRP laminates. Compared with other loading methods, the damage area, damage depth and damage volume caused by extended moving loading are in good agreement with the test results. The effects of current expanding and movement should be taken into account when simulating lightning strike ablation damage of composite materials. Keywords: composite; lightning strike; ablation damage; finite element model; current loading method