Based on the unstructured quadtree rectangular grid,the paper built a depth-averaged 2D hydrodynamic model with implicit scheme.It calculated the movement track of pollutant of water body through Lagrangian method and random walk principle.The hydrodynamic model used the finite volume method and non-staggered system with the Rhie and Chow's interpolation to eliminate the checkerboard pressure problem.The SIMPLEC algorithm on non-staggered grid was used to derive the water level correction equation. The coupling model was tested by hydrodynamic of idealized estuary,oil slick transport under the effect of wind and flow.The mode was also used to calculate the hydrodynamic characteristics of north yellow sea Zhuanghe breeding waters and the transport process and trajectory of pollutant in sea. Finally,it gave the transport rule of contaminant in the simulated area.The research result has important significance for the water environment management of Zhuanghe breeding sea area.