Abrasive flow machining (AFM) was proposed to finish the problems of high capital cost and low efficiency of surface polishing on the aero-engine blisk. By establishing the simulation model based on whether the blisk fixture tool contains the core mold and the gland, and compared the distribution law of the flow field in the simulation, redesigned the fixture structure to fit for the blisk. On this basis, the AFM processing experiment is carried out. The result shows that after adding the core mold and the gland structure, the AFM process can effectively improve the local flow field of the blisk, and solve the problem of the inconsistent processing effect and abrasive erosion on the sharp edge. The surface roughness of the flow channel is reduced by 0.6μm, and the surface quality has been further improved.