Spur dike is one of the various technologies utilized in river rehabilitation. Spur dike provides many advantages, such as promoting aquatic habitat, improving channel for navigation, and protecting the stream banks. This study serves to evaluate the effect of a spur dike on the formation of sand bars in a straight rectangular channel fed by suspended sediment. The performance of spur dike in inducing the formation of spur dike is investigated under three different spur dike angles. A three-dimensional (3D) model was developed using Flow-3D® to investigate the flow depth and velocity around spur dike. Based on the velocity distribution, the influence of spur dike angle on the formation of sand bar was explained. A scalar concentration is used to represent the suspended sediment in the simulation, and the formation of sand bar is represented by the scalar concentration. According to the numerical results, the 90° spur dike produced a larger and longer sand bar than the 45° and 135° spur dikes.