In order to obtain the influence law of stand column types on flow and separation performance in a vortex settling basin (VSB), VSBs without column support system, with II-type and VSB H-type stand columns were studied by model experiments respectively. The results show that in the case without columns, the air core penetrates through the flushing bottom with the largest air core diameter, the maximal clean water area and the strongest spiral flow intensity. The air core offsets the flushing bottom after the installation of II-type columns, leading to smaller air core diameter, clean water area reduction and lower spiral flow intensity. The offset distance of air core is the largest after installation of type-H columns, leading to the smallest air core diameter, minimum clean water area and weakest spiral flow intensity. Compared with H-type columns, the sediment trapping efficiency, flushing efficiency, sediment deposition in the basin, water abstraction ratio under the II-type column system are similar to those without columns under deflector. II-type columns can be used as the support body shape to ensure the safety of the deflector and a higher sediment trapping efficiency.