The invention provides a light-medium high-energy-head compressor model stage with a flow coefficient being 0.0571. The light-medium high-energy-head compressor model stage with the flow coefficient being 0.0571 comprises an impeller, a blade diffuser, a bend and a return device. The impeller is located at an inlet position of the model stage; the blade diffuser is arranged on an outlet of the impeller; the return device is located at an outlet position of the model stage; the blade diffuser communicates with the return device through the bend; a machine mach number Ma2 of the model stage is equal to 0.2 to 0.65; the flow coefficient phi 1 of a design point is equal to 0.0571; an energy head coefficient tau of the design point is equal to 0.702; the polytropic efficiency etapc1 under a designed flow coefficient working condition is equal to 0.882; and an applied flow range is 0.65 to 1.67 of the design point. The invention further provides a design method of the model stage. The modelstage provided by the invention is high in efficiency, high in energy head coefficient, large in hub ratio and small in span; and by adopting the model stage, a light-medium compressor can have higheroperating efficiency and a wider working condition range, meanwhile, the working speed of a rotor is reduced, a bearing span is shortened, and the stability of the rotor is improved.