Abstract: Oil spill accidents under complex sea conditions, with the joint action of waves, currents, and wind, will cause significant economic losses and environmental damage. In this paper, three-dimensional numerical calculations of the N-S equation and the k-ɛ turbulence model, based on the VOF method, are conducted to study the oil spilled migration and diffusion behavior under complex sea conditions. The results reveal that the buoyancy process of oil spilled is less influenced by the wavelength and wind speed, which mainly affect the oil spilled drift process on the sea surface. The underwater deflection and surface drift motion of oil spilled are primarily dominated by the current speed. When the current speed is greater, it takes more time for the oil spilled to reach the water surface, the deflection angle of the underwater movement trajectory is larger and the oil droplets disperse more. After the oil spilled reaches the sea surface, when the wind and current speed is higher and the wavelength is longer, the oil spilled will drift farther on the sea surface, but the degree of lateral diffusion will be smaller. The results can provide a reference for oil spill accident handling and improve the efficiency of oil spill emergency response actions.