Abstract: An unstructured mesh finite volume oceanic model is used to simulate the water exchange capacity and oil spill in Zhuyu Bay of Pingtan. The results show that the halflife time of most waters in Zhuyu Bay is less than 1 day. The average residence time is about 3 days and the water body flushing time is about 15 days. It shows that the water exchange capacity in the bay is strong. The spatial distributions of particle trajectories affer oil spill over 48 h show that the oil particle sweeping range and trajectories are closely related to the oil release time and the action of wind. Under calm wind conditions, the oil spill route is mainly affected by local tidal currents showing a southnorth reciprocating motion. Under the adverse wind conditions, the oil particles can spread to Tannan Bay, Caoyu Island, Tangyu Island and Gaoshan Bay of Pingtan and as far as to the northwest of Nanri Island.