Abstract: Aiming at the last two stage of a high-pressure compressor,co-flow jets stator is designed to match the tandem rotor which has been existed,and then,the stator and rotor are combined to be a highly-loaded stage.During the design of the co-flow jets jet stator,the influence of co-flow jets location and denseness is studied.It is proved that the highly-loaded stator can prevent from separating while reaching a diffusion factor of 0.9 in the paper.It is indicated that co-flow jets can effectively control separation which is began from about 49% of axial chord length shown in the numerical calculation.The best co-flow jets location is just somewhere at the rear of the separation point.The final combined highly-loaded stage can hit the target of achieving the work of a two-stage ordinary compressor and obtain high adiabatic efficiency as well.