Abstract: Under the conditions of high-altitude and low-Ma,the low-Re number affects the performance of the fan/compressor greatly.In order to analyse the effect of low-Reynolds number on the performance of some fans,Wassell semi-empirical method and 3D numerical simulation method have been employed to study the aerodynamic performance and flow field structure of the fan.For the sake of denting the influence of low-Reynolds number,the stator aerofoil was redesigned and the effect of the modified design was evaluated.