The range of Reynolds number has a great influence on the calculation of turbulent width around bridge pier,which will affect the rationality of the calculation results.For the mountain rivers,the Lattice Boltzmann Model(LBM)is used to simulate three dimensional turbulent flow field of bridge pier with supercritical Reynolds number.Combining with large eddy simulation and moving boundary treatment method,we analysed three dimensional turbulent width of bridge piers under different flow and river conditions.Based on the results, the coupling relationship between the circular piers the relative turbulent width and the Froude number in the straight channel and the curved channel is established.Through the waterway width checking of Sichuan Dengjiaba bridge,compared with the empirical method and Zu Xiaoyong algorithm,we find that the turbulence width is smaller and more reasonable.