In order to research the influence of adjustable vane on the aerodynamic performance of the ram-rotor test system,FLUENT software has been adopted to simulate the flow passage of the ram-rotor test system numerically.The vane opening is controlled by changing the stagger angle of the vane blades.Results show that flow uniformity of vane outlet is influenced by the vane openings,which has an impact on the aerodynamic loss to some extent.Total pressure ratio,adiabatic efficiency and mass flow rate can be regulated by different openings of the vane.Compared with-8° vane opening,top efBciency of the ram-rotor increases by about 13.8%at +6° opening.And total pressure ratio drops by 5.87%.The rising opening increases the relative Mach number at inlet of the ram-rotor and weakens the intensity of the tip clearance leakage,which comes to a decreasing aerodynamic loss. In order to research the influence of adjustable vane on the aerodynamic performance of the ram-rotor test system, FLUENT software has been to simulate the flow passage of the ram-rotor test system numerically. Vane opening is controlled by changing the stagger angle of the vane outlets. Results show that flow uniformity of vane outlet is influenced by the vane openings, which has an impact on the aerodynamic loss to some extent. Total pressure ratio, adiabatic efficiency and mass flow rate can be regulated by different openings of the vane.Compared with-8 ° vane opening, top efBciency of the ram-rotor increases by about 13.8% at + 6 ° opening. At total pressure ratio drops by 5.87%. The rising opening increases the relative Mach number at inlet of the ram -rotor and weakens the intensity of the tip clearance leakage, which comes to a decreasing aerodynamic loss.