To further improve the polished quality of blades surface, a new polishing process-ultrasonic vibration assisted belt flapwheel flexible polishing (UBFP) is proposed in this paper. The trajectory state of abrasives and the continuous polishing process were analyzed, and the interlace phenomenon was described. The influences of main parameters on the quality of machined surface were discussed through experiments, and the prediction models of surface roughness(Ra and Rz) were established. The results showed that lower surface roughness and less polishing marks could be achieved by UBFP, and the models were reliable that can be used in further processing and research. This study can be considered as a theoretical and experimental reference to advancing the polishing surface quality of the blisk blade.