Abstract: This paper predicts and analyzes the impact of spilled oil slick on the surrounding sea area base on the possible oil spill accident of the Australian live cows processing program in Zhoushan, Zhejiang.A two-dimensional tidal current model of Zhoushan sea area is established using MIKE21 HD module and verified by the measured hydrological data.On this basis, MIKE OS module is used to simulate the spreading, transfer, and weathering processes of the oil slick.Such processes are calculated under different conditions for the oil spill that happened in the channel and the berthing platform.The results show that spreading and transfer of oil slick are related to leakage locations, spill time, current field, wind speed and wind direction.Under the condition of no wind, the movement of oil slick is dominated by flood and ebb, with a maximum sweeping area of 195.74 km² within 24 hours.Under the condition of prevailing wind direction of SE in summer, oil slick transfers to the open waters of Hangzhou bay.Its spreading range is wider because it is not blocked by coastlines and islands.The maximum sweeping area reaches 209.71 km² within 24 hours.Under the other condition with unfavorable wind direction of NW, the oil slick piles up along the coastline of the south of Jintang island and surrounding islands with a maximum sweeping area of 131.99 km² within 24 hours.