In order to predict the transport processes and distribution laws of point source pollutants in continuous bend flow when water pollution accidents occurs, a three-dimensional continuous bend flow pollutant transport model was constructed using the WALE-based large eddy simulation method. Numerical simulations were conducted under four different Reynolds number conditions to investigate the hydrodynamic structures and transport characteristics of point-source pollutants. The effects of Reynolds number variation on hydrodynamic structure and turbulence characteristics were analyzed. By comparing the spatial distribution characteristics and mixing rates of point-source pollutants in the lower reaches of curved channel under different Reynolds number conditions, the transport mechanisms of pollutants under the combined action of secondary circulation and turbulent transport were revealed. The results show that with the increase of the Reynolds number, the average circulation intensity on the cross-section is weakened, and the flow structure becomes more uniform. The average lateral and vertical dispersion coefficients of pollutants along the route are exponentially negatively correlated with the Reynolds number. The spatial mixing degree of pollutants is positively correlated with the Reynolds number. The percentage of fully mixed area of pollutants is negatively correlated with the Reynolds number.