This research presents a tridimensional acceleration sensor based on flexure parallel mechanism (FPM). Three perpendicular compliant limbs with compact monolithic structure are developed to serve as the elastic component for acquiring the inertial signals in each direction. With integrated flexure hinges, each chain containing multiple revolute joints and cantilever beams are designed to carry compressive and tensile loads. First, the structure evolution and kinematics modeling are introduced, followed by the multispring modeling of the directional compliance for the flexure limb. Then, the comprehensive finite-element analysis (FEA) including the strain of the sensitive limbs, modal analysis for total deformation under different frequency is conducted. The compliances calculated by FEA and multispring model are compared. Finally, the dimensional optimization is implemented based on multipopulation genetic algorithm to obtain the optimal flexure parameters. The proposed methods and algorithms are also useful for the analysis and development of other flexure parallel mechanisms.