CFD method is used to simulate characteristics of flow field inner a kind of wave-plate gas-liquid separator with drainage channels. The N-S equations closed with standard turbulence model is used. The resistance characteristic of separators with different vane clearances is acquired as function of inlet velocity and the flow fields are simulated numerically. In order to evaluate the simulation method, model experiment is carried on using wind-tunnel to obtain the resistance characteristic under the same operation condition. Good agreement is reached between numerical results and experimental data of pressure drop of the separator. The research can provide theoretic basis for the design and optimization of wave-plate gas-liquid separator in the future.