The rapid development of the automotive industry calls for large demands for fixtures with high modularity and full flexibility. A novel reconfigurable modular fixture is proposed in this article. The fixture, which provides high loading capacity, is designed based on the kinematic characteristics of dead point of linkage. The redundant actuation is introduced to increase the reliability of the mechanism. Kinematics of the loading mechanism is modeled and analyzed. The stiffness model of the mechanism is established through assembling the stiffness matrix of different links. Both kinematic parameters and structural parameters are optimized synchronously for obtaining the minimum deformations of the mechanism subject to constraints on volume and mass. The prototype of the developed fixture is designed and its comprehensive performance is analyzed. The modular design allows easier maintenance and replacement of the mechanism. The proposed design can also be utilized to other industrial applications.