Abstract: Currents and waves are the primary dynamic forces for the diffusion of underwater oil spills. This study utilized numerical simulation methods to construct a two-dimensional flume model, aiming to investigate the process of drift diffusion of crude oil from the submarine to the surface in the presence of pure currents, pure waves, and the combined influence of waves and currents. The results reveal that under wave-current coupling, the diffusion of oil spills exhibits characteristics of oil particle movement observed under both pure currents and pure waves. Oil particles oscillate with water quality points and simultaneously diffuse in the direction of the water current. As oil particles ascend, the friction and mixing action from the water body become more pronounced. When oil particles reach a turning point where the slope changes, the trajectory of the oil spill begins to tilt in the direction of the water current. Furthermore, as the oil spill volume increases, the entrainment effect becomes more significant, leading to increased lateral and vertical dispersion of oil particles. The findings of this study can serve as a reference for emergency response strategies in oil spill incidents.