Aerodynamic design and numerical simulation were carried out to investigate a intermediate transition duct (ITD). Results of the analyses and comparisons showed that the thickness distribution of ITD strut vane(SV) had little impact on the main flow when SV number was small，while the pressure gradient and separation of SV surface were affected mainly through the profile curvature distribution. The flow separation in the region of hub

shroud and SVs tip was controlled effectively with the combination of concave and convex curvature. The stagger angles of the SV on S1 stream surface were changed by circumferential lean to impact the effect of attack angle and depress the flow separation. The SV should be placed in the main flow with low pressure gradient as more as possible no matter part or all to decrease the pressure gradient and risk of flow separation.