Because of complex shape of swing bolster of maglev vehicle that running at 500 km·h-1 speed with severe vibration and dynamic load, the defects, such as under filling and metal-folding in the forging process will be caused if the blank is not designed in a practical manner. A numerical simulation of swing bolster was conducted using Deform-3D package, and the optimal shape of blank, which could avoid defects caused by unreasonable metal flow, was obtained through investigating the simulation results repeatedly. Moreover, an experiment was performed using the optimal shape of blank, which took into account the loss of volume caused by remeshing. A good quality forging, which shows an agreement with the simulation results, is obtained by experiment, and this method could be used in optimizing the complex shape of blank in forging.