To provide precise simulation for the flow field of steam turbine last stage, the calculation method for the vapor-liquid two-phase non-equilibrium condensing flow was developed based on the two-fluid model. The numerical simulation of moisture removal slot on the surface of a steam turbine last stage blades was carried out, and the influence of different moisture removal slot structures on the non-equilibrium condensing flow of turbine cascade was analyzed. The results show that the moisture removal slot set on the blade suction surface can effectively reduce the nucleation rate of water droplets near the throat region of cascade,therefore decrease the loss of non-equilibrium condensation caused by phase transition,significantly reduce the number of larger diameter water droplets at the outlet of the blade cascade. Due to larger inflow width and more reasonable moisture removal structure, the scheme II is more beneficial to improve the suction effect of the water film on the surface of long blade in the wet steam stage.