In order to learn aerodynamic performance of swept blade, the super-critical steam turbine high stage cascades were selected as prototype blade (PB). Chord-wise fore-sweep blade (SWF) and chord-wise aft-swept blade (SWB) were constructed and conduct off-design working condition numerical simulation of prototype, forward-swept and aft-swept blade stages respectively. The simulation results indicated that three cascades stages maintain a good aerodynamic performance in a wide range of inlet-flow. Forward-swept stage has the highest isentropic efficiency and smallest axial thrust than the other two.