Abstract: The lightning protection of wind turbine blades is the key to ensuring the safe operation of wind turbines.Due to the uncertainty and randomness of the development of lightning, this paper proposes to use fractal theory to analyze the physical process of lightning strikes on wind turbine blades, and consider the impact of polluted attached blades on lightning strike failure. First, a fractal model of lightning is established to simulate the lightning strike process of wind turbine blades. Then, the influence of different blade angles on blade lightning strikes is analyzed. At last, the impact of pollution adhering to blades on the distribution of blade electric field is considered to obtain the variation law of pollution on lightning strike failure. The research results indicate that when a three blade wind turbine is struck by lightning, the probability of lightning strikes on the three blades is not consistent.The probability of lightning strikes on the vertically upward blade is significantly higher than the other two blades.The rotation angle of the blade causes a change in its electric field strength, and as the rotation angle of the blade increases, its lightning triggering ability gradually strengthens. At the same time, when pollution adheres to the blades, the background electric field of the wind turbine blades is distorted, and the electric field strength further increases, leading to the expansion of the lightning strike area. The relevant results can provide theoretical basis for the establishment of modern wind turbines and lightning protection.