A method was developed by combining intelligent optimization algorithm and quasi-three dimensional cascade calculation programme

and an aspirated compressor airfoil was optimized using this method. And there was a detailed analysis of changes in the original and optimized flow fields. Optimized airfoil can make the total pressure loss reduce by 40% and the static pressure ratio increase by 0.6%.The best suction position locates in upstream the start position of the separation region

and the optimized airfoil has more uniform load distribution. In addition

the performance of optimized airfoil has a great improvement within the whole incidence angle range. The results show that more uniform load distribution can improve the airfoil performance

decrease the separation region and reduce the energy output on suction. For the airfoil with a small separation region in trailing edge

the best suction location is located upstream the start position of the separation region.