In order to take effective measures in time to alleviate and control the oil pollution and minimize the damage after the accidents, Environmental Fluid Dynamic Code(EFDC)was applied to simulate the oil spill risk occurred in Jingjiang section in the downstream area of Yangtze River. Through EFDC, two-dimensional hydrodynamic of this section was accurately simulated. Considering the flow fields, wind fields and complex topographic conditions, Lagrange tracking method was used to calculate the oil film trajectory after oil spilling into the river, as well as the arrival and leave time to the Reserve in the downstream. The results showed that the oil film was stretched gradually along the flow direction, whose coverage area increased gradually, which was influenced by the terrain condition of Yangtze River. In the tide sect of the Yangtze River, flow fields played a dominant role in oil pollution diffusion, and wind fields also had an impact on oil pollution diffusion. The oil film moved downstream in terms of drift oscillation due to the alternative flood tide and ebb tide. When oil spill accident occurred in different flow field, the drift velocity of oil film was different. The oil film spread downstream faster when oil spill accident occurred at ebb tide. The larger the wind speed in the worst wind direction, the faster the oil film drifted downstream.