The highly loaded diffuser compressor cascade with a full-span suction slot was numerically simulated under five different chordwise suction positions in the first step. The influences of aerodynamic parameters such as suction position on the suction flow distribution were studied in detail. Then experiments on the effects of partly-span suction flow on the performance of a three-dimensional cascade were carried out. The simulation region includs the inner cavity of the suctior blade

and the boundary conditions in simulations are set according to the experimental conditions. The suction flow is C-type distributed along the spanwise direction in full-span suction schemes. Both of the partly-span suction schemes mainly improve the flow field around the midspan

while the suction flow around the blade roots also suppress the back flow in the corner region. Both the three-dimensional flow field of the cascade passage and inner cavity of the aspirate blade influenced the spanwise distribution of the suction flow. Therefore it is necessary to design tailored suction slots/orifices according to the characteristics of the three-dimensional high loading diffuser compressor cascades.