Abstract: Numerical study of the effects of suction location and suction flow rate on performance of low-speed compressor cascade with large turning angles shows that with the same inlet Mach number,the optimal suction location,corresponding to the least cascade total loss,exists at a lower suction flow rate,and the decrease of total loss is not sensitive to the suction location at a higher level of suction flow rate.As suction flow rate increases,the accumulation of low energy fluid in the suction corner is alleviated,and the flow turning as well as the cascade load increases,therefore,total loss is reduced by 28.2% at most.The diffusion recovery due to the boundary layer suction and the separation of passage vortex are two main factors for the selection of the optimal suction location and suction flow rate.