The paper-feeding mechanism of sheet-fed offset press was analyzed to find the design link which should be improved to increase the maximum printing speed. The experimental modal method was applied to analyze the paper-feeding mechanism of sheet-fed offset press, and the experimental modal analysis technique was introduced into the solution of dynamic response of the paper-feeding mechanism. The solution was then used to guide and improve the design. When there was prototype for testing, the modeling accuracy of the experimental modal analysis technique was higher than the common single degree of freedom lumped mass method. Correspondingly, more accurate method could be achieved by test analysis of the system. Application of this method increased the maximum speed of one kind of sheet-fed offset press from 13 000 sheet/hour to 16 500 sheet/hour. Experimental modal analysis method could provide reference for the improvement design of offset press. It is not only an effective supplementation to structural design and dynamic design, but also a tool for checking. This method could also be applied in the analysis and study on other key mechanisms such as paper-feeding head, front lay mechanism and cam-linkage mechanisms like open-close gripper mechanism.