Abstract: Cyclone column separator is a kind of high-efficiency separation equipment widely used in the field of gravity separation of fine-grained and has showed perfect separation effects for coarse coal slime and coal gasification slags. Objective In order to study the influence of the feeding structure on the internal flow field and particle separation effect of the cyclone column, Methodin this article, two types of cyclone column separators were developed with horizontal tangential and rounded spiral feeding structure, and was investigated by numerical simulation analysis using fluent software and laboratory separation experiments as well. Result The results of flow field simulation show that at the same feeding pressure, the rounded spiral feeding makes the internal flow field of cyclone column have higher static pressure, tangential velocity and downward axial velocity, which helps to improve the accuracy of particle separation by density. The results of the separation experiments on coal gasification slag show that the cyclone column with round-angle spiral feeding presents larger capacity and higher separation accuracy for coarse particles than that of traditional tangential feeding at the same feeding pressure. When the inserting depth of vortex finder is 105, 135 and 165 mm, the separating efficiency of >0.125 mm particles increased 3.32%, 2.50% and 5.35%, respectively, compared with the traditional tangential feeding structure. Conclusion Changing the feeding structure provides a new technical way for cyclone column separators to further improve their separation efficiency.