Abstract: With the use of 3-D viscous flow analysis technology,this paper analyzed the separation losses and stall margin at design speed and off-design condition,by changing the angle of inlet guide vane and stator.In the event of matching of stagger angle between inlet guide vane and stator,the change tendency and characteristics of compressor efficiency and stall were investigated.It shows the linkage controlling scheme of vane-stator is related to rotating speed.The result provides a basic standard for scheme design of self-adaptive control in practice.