The invention provides a dynamics analysis method for an eight-connecting-rod mechanical press. The dynamics analysis method comprises the following steps: simplifying a transmission mechanism model;carrying out stress analysis on each rod of the transmission mechanism to obtain the stress condition of each rod; listing a virtual work equation by utilizing a virtual work principle according to the stress condition of each rod; substituting kinematic parameters and press tonnage information into the virtual work equation and performing solving to obtain a crank torque solving curve; performingsimulation processing according to the three-dimensional model of the transmission mechanism to obtain a crank torque simulation curve; verifying whether the solving curve of the crank torque is consistent with the simulation curve or not, and if yes, respectively outputting crank torque solving parameters. The method adopts the virtual work principle to perform dynamic analysis to obtain the crank torque, is simple to solve, and improves the calculation efficiency.