Dynamic modeling and mechanics analysis of a novel pneumatic muscle driven parallel mechanism for imitating human pelvis (PMPMHP) is investigated. The PMPMHP has some advantages for both parallel structure and pneumatic muscle actuator. To begin with, the kinematic model of the PMPMHP is introduced and the dimensions of the PMPMHP are optimized by using genetic algorithm. Then, the dynamic model is developed on the basis of Newton–Euler method and ideal gas law. After that the workspace, singularity and stiffness of the PMPMHP are analyzed. At the end, simulation results indicate the feasible operation performances of the PMPMHP. This mechanism can be further utilized either for rehabilitation therapy of human pelvises or for humanoid robot design of the pelvis part.