ABSTRACT In this study, high gravity, regarded as a process intensification technology, is integrated into the conventional cyclone through a rotary drum, leading to the design of a novel gas–liquid separator called high‐gravity cyclone separator (HGCS) for natural gas dehydration and purification. The flow field is numerically investigated to characterize the separation performance. A novel quality factor is proposed to assess the relationship between the separation efficiency and pressure drop, where the effects of operating parameters and drum dimensions are experimentally evaluated to determine the optimal conditions. The results indicate that both the velocities and pressures within the rotary drum can be enhanced by increasing the radial position. Specifically, an increase in inlet velocity leads to a reduction in tangential velocity while simultaneously improving axial velocity. In the barrel and conical regions, a lower inlet velocity significantly influences the quasi‐free vortex and the ascending gas, whereas a higher inlet velocity may worsen the pressure distribution. For optimal separation with the highest quality factor, it is recommended that the inlet velocity be maintained at 12 m/s, with ideal high‐gravity factors and liquid concentrations of 59.4 and 57 g/m 3 , respectively. Furthermore, increasing the radial height can enhance separation performance, with a height of 8 mm being optimal for low velocities. It is crucial to avoid excessively short or long drums that a length of 190 mm is recommended.