The study is aimed at improvement of efficiency of a gas-liquid separator operating at the pressure of 2.5 MPa and high flux density in the cyclone body. The submitted schematic construction of the separator provides the reduced dynamic head of gas in the zones with increased liquid phase concentration and prevents the entrainment of separated liquid to the outlet receiver. The receiver consisting of a conical converging channel and an externally finned circular pipe is located in the middle of cylindrical cyclone body. A fin-and-tube flow conditioner is mounted upstream of the converging channel inlet. Detailed flow structure in the separator has been obtained from numerical study based on Reynolds-averaged Navier-Stokes equations with anisotropic Reynolds stress turbulence model. Simulation results were involved in estimation of the main performance characteristics of the separator and probability of droplet entrainment and upwards flowing film. Experimental research on a 1:2 separator model allowed estimation of separation efficiency and flow resistance coefficient of the separator. (C) 2018 Elsevier B.V. All rights reserved.