It＇s　important　to　evaluate　the　influences　of　non-equilibrium　condensation　on　the　geometrical　and　aerodynamic　design　of　steam　turbine.　A　non-equilibrium　streamline　curvature　throughflow　calculation　program　is　developed　and　applied　to　analyze　the　wet　steam　flow　in　the　low　pressure　cylinder　of　a　300　MW　steam　turbine.　Compared　with　the　equilibrium　condensing　flow,　the　non-equilibrium　one　shows　obvious　changes　in　the　distributions　of　the　surface　pressure,　outlet　flow　angle,　wetness　fraction,　as　well　as　the　stage＇s　reaction　degree　and　efficiency.　The　non-equilibrium　condensation　leads　to　decreased　efficiency　by　2.08%　and　degraded　power　output　by　1.05　MW.　The　presented　program　provides　a　tool　for　the　design　of　large　scale　wet　steam　turbine.