Abstract: In order to study the influences of the spur dike length on the local scour of riverbed in the natural rivers, based on the shape of the natural river channels and the actual layout of the spur dikes, a three-dimensional computational fluid dynamics (CFD) numerical simulation method for the local scour of the spur dike group suitable for the shape of the natural river channel is proposed, and a three-dimensional model for the spur dike group located at the Maliangzi section of the Luanhe River in Hebei Province is established. The shape and erosion depth of the scouring pit in the groin head are numerically simulated by using RNG k-ε model and VOF method which can track the free surface. The shape and scouring depth of the scouring sump are numerically simulated. The numerical simulation results are in good agreement with the measured values, and the reliability of the numerical model is verified. The maximum scouring pit depth and scope of the spur dikes are obviously reduced after adjustment.