Abstract: Both selection of suitable support and interference correction are the key to subjects of high speed wind tunnel test technique for transport aircraft. Support interference of airfoil strut support and different angle sting supports on the aerodynamic characteristics of transport aircraft was studied by theoretical calculation, force measurement and pressure measurement. The interference of 0°, 5°, 15°, 30° dummy sting supports was obtained by airfoil strut support test and vertical tail support test. The interference of dummy airfoil strut support was obtained by 0° sting support test. The investigation indicates:the agreement is good between 0°/5° sting support test results and frontal-attachment-location airfoil strut support test results with support interference corrections for transport aircraft, 0°/5° sting support test results with support interference corrections are reliable; 0°/5° sting support, support interference of which is obtained by frontal-attachment-location airfoil strut support test, is a rational support for transport aircraft in high speed wind tunnel; the error of large-angle-sting support test results with support interference corrections such as 30° sting support is relatively severe. Strong body vortices are formed on the leeward side of large-angle-sting support, large-angle-sting support body vortices interact with the flow pattern of transport aircraft tail. For this reason, it is difficult to obtain large-angle-sting support interference correction accurately, and large-angle-sting support is unsuitable for transport aircraft in high speed wind tunnel.