Aiming at the problem that the Euler-Lagrangian method can not predict the influence of the re-entrainment phenomenon on the demister performance in the numerical study，the study established a demister model based on re-entrainment phenomenon by taking wave-plate demister as the research object and coupling Euler Wall Film model on the basis of Euler-Lagrange method． Through the experimental data comparison，the model prediction curve is consistent with the experimental results． The effects of plate spacing and turning angle on the demisting performance were studied in different flow rates by the improved model． The results show that the liquid film separation at the corner is the main reason for the reduction of droplets removal efficiency at high flow rates; increasing the plate spacing and turning angle will aggravate the re-entrainment and decrease the critical velocity; below the critical velocity，the droplets removal efficiency decreases with the increase of the plate spacing，and increases with the increase of the turning angle; above the critical velocity，the droplets removal efficiency decreases with the increase of the plate spacing and the turning angle． The optimal value of the plate spacing and the turning angle is 20mm and 40°． In this situation，the droplets removal efficiency can be increased by 16. 38% ，and the pressure drop can be reduced by 9. 74% ． This result can be used to prevent the demister from re-entrainment phenomenon and improve the demister performance．