In order to compare the difference between the single-stage separator and the two-stage separator, and find out the reasons that the two-stage series separator was not ideal, the two-stage series structure was constructed by using vortex gas-liquid separator as prototype, and through coupling boundary condition, using the Euler-PBM model to establish the numerical simulation model of the two-stage eddy current separator. The simulation results showed that the gas separation effect of the two-stage series separator was better than that of the single-stage separator, but the internal pressure of the two-stage separator was smaller than that of the casing tubing annulus at the corresponding position, which led to the return phenomenon at the vent hole. The outlet of the upper separator had a large pressure difference, the high flow rate and gas-liquid ratio resulted in a significant reduction to the gas separation efficiency of the two-stage separator. When the gas-bearing ratio at the inlet reached 90.0%, the separator failed. The research results had important practical significance for widening the application conditions of ESP, and the research methods had important reference for similar tool simulation.