Several new arc-shaped vortex finder structures were developed to restrain the circulation flow and reduce short-circuit flow. These problems were investigated by conducting laboratory experiments and using a computational fluid dynamics numerical simulation method. To verify the accuracy of the numerical simulation, a typeA vortex finder was employed to perform a particle image velocimetry test under identical working conditions. Then, these new structures were compared with a typeO vortex finder to reveal the differences in pressure field, velocity field, and separation performance. The arc-shaped vortex finder was able to restrain the circulation flow and reduce the maximum pressure drop at the outer wall of the vortex finder.