In order to improve the separation efficiency of oily wastewater, a new type of cyclonic flotation column is proposed, which combines low-intensity swirl with air flotation. A computational fluid dynamics (CFD) simulation is conducted to evaluate the performance of the cyclonic flotation column. the population balance model (PBM) is used to provide and describe the initial flow field, bubble distribution, and the Lagrangian particle tracking (LPT) model is used to predict the separation efficiency and movement of oil droplets with different diameters trajectory. Numerical simulation results show that the collision efficiency of bubbles and oil droplets can be promoted by the increase of the turbulent intensity, which can accelerate the oil-water separation process. For small diameter oil droplets (10 µm), the separation efficiency can also reach 92%. The CFD model is validated against the experimental results, which indicates that the numerical simulation method is stable and reliable.