With the high manoeuvrability requirements of modern aircraft and the introduction of S-curve intakes， the problem of flow field distortion in engine intakes has become increasingly prominent， and accurately modelling the total pressure distortion at the aerodynamic interface plane （AIP） interface of the engine inlet on the ground test stand has become more challenging. In this paper， based on a new type of hinged total pressure distortion simulator with variable opening angle proposed by the Arnold Engineering Development Centre in USA， the main geometric parameters of the hinge and the incoming Mach number on the steady-state distortion flow field are analyzed in detail using the Reynolds-averaged Navier-Stokes （RANS） numerical method， and the vortex development and total pressure pulsation characteristics downstream of the hinge are studied using the more accurate DES method. By serrated reshaping of the original hinge， the mixing between the wake and the main flow region is enhanced while the steady-state distortion flow field remains largely unchanged， effectively reducing the dynamic distortion index of the downstream flow field and extending the simulation range of the steady/dynamic distortion ratio.