To investigate the influence on bridge scour from environments, a K-ε turbulence model was applied in the present study to simulate the complicated flow filed and local scour around bridge pier. Four key problems for a fine 3D scour simulation were discussed in details and the corresponding solutions were also given. More attentions were especially paid to the dynamic updating of boundary condition and the optimized iteration convergence of programing algorithm. The accuracy of the proposed simulation was fully verified by comparing to the classic B. W. Melville experiment from the viewpoint of 3D performance during the scour. By re-developing the CFD Fluent program following the proposed solution, a parametric study was conducted by varying several scour environment parameters. The results show that the maximum scour depth has an approximate linear relationship with the pier measurements and average velocity of flow. A good selection of pier shapes, a narrow effective pier width, a slow average velocity of flow, and a proper water depth would all reduce the scour depth of piers. A conclusion can also be drawn regarding the influences of different environment parameters on the 3D scour development, which should be a rational theoretical basis for the active anti-scour design for piers.