In order to provide a reference for the new aerodynamic configuration design of the axialflow compressor, and to further control the corner separation of the compressor, the effect of alternatingstator on the aerodynamic performance of a transonic compressor was detailly studied. Taking NASA stage35 singlestage axial compressor as the model, based on the theoretical method of control angle separation, the inlet geometric angle of the profile at stator tip was adjusted, and a new type of alternatingstator configuration was constructed for numerical simulation. The aerodynamic characteristics of the modified compressor was analyzed in detail. The results show that different alternatingstator models have different performances on controlling the corner separation. Compared with the original and the fullannulus modified compressor, the alternatingstator can effectively improve the compressor performance, and realize the enlargement of the stall margin and the improvement of the total pressure ratio and equal entropy efficiency of compressor. When the inlet geometric angle of the alternatingstator is reduced by 21°, the compressor has the largest performance improvement, the total pressure ratio and the isentropic efficiency of the compressor are greatly improved and the compressor has the largest improvement in stall margin. Compared with the original compressor, the stall margin is increased by 4.8%.