To reduce the high-frequency noise of the paper folding board for the automatic book packer. In this paper,the finite element software COSMOSWorks was used for dynamic modeling of vibration of fixed folding board and the vibration modal was analyzed. Through the analysis, natural frequency components of order 1~6 were determined, and improvement measures were proposed. The results showed that the natural frequency of vibration of the folding board was reduced, falling into the frequency range of low-frequency noise. The natural frequency of the first 6 orders decreased to below 200HZ. The solution proposed in this paper to use silencer holes to reduce high-frequency noise was proven to be effective, which provides reference for noise reduction optimization of other parts of the book packing machine.