Abstract: To discuss the transition part deformation of installing test equipment at AIP during inlet/engine compatibility flight tests, an evaluation index of transition part radial deformation is developed and applied in engineering calculation. Moreover, influences of perforating, installing static pressure base and total pressure test rake on the radial size of the transition part are compared and analyzed. Accordingly, it is indicated that installing pressure test device at AIP may force the radial size to deviate from the designed value and standard circle; welding static pressure test base may introduce obvious deformation while riveting may introduce less deformation relatively; restricting on both sides of the total pressure test rake may not seriously influence the radial size whereas effectively restrain its vibration amplitude. The optimized installation scheme of the pressure measuring device has been adopted in engineering.