To realize the rigid dynamics modeling of a novel 4-UPS (universal joints-prismatic pairs-spherical joints)-RPU (revolution joints-prismatic pairs-universal joints) spatial 4-degree of freedom redundant actuation parallel mechanism, the Lagrange method was adopted. Firstly, the expression of kinetic energy and potential energy of 4-UPS-RPU redundant actuation parallel mechanism were educed, and the equivalent generalized force of non conservative force was analyzed. Secondly, the dynamics model of 4-UPS-RPU redundant actuation parallel mechanism was established by the Lagrange method, which was the foundation of the solution of driving force and dynamic analysis. Finally, the driving forces of 4-UPS-RPU spatial 4-degree of freedom redundant actuation parallel mechanism were solved by theoretical calculation and virtual simulation combined with examples, respectively. The numerical results obtained by solving the dynamics model of the 4-UPS-RPU parallel mechanism by Matlab were in agreement well with the virtual simulation results by ADAMS. The results can provide theoretical basis for dynamic optimization design and control of 4-UPS-RPU parallel mechanism, and also suggest a way of thinking about rigid body dynamics modeling for other redundant actuation spatial parallel mechanism.