Compared with sewing machine driven by traditional match motor, industry sewing machine driven by AH20 motor have economy energy, intelligent degree, install convenience, operation simple and ability completely etc. It has vast applied foreground and huge market potential. But the lifting up structure has problems of vibration and noises in use, and seriously obstructed the progress of its market expansion. The causes were found through theoretical calculation, modal analysis and experiment analysis, and the structure was improved. The experiment results confirmed the validity of the changes.