There has been a growing interest of parallel mechanisms which offer a high degree of precision, stiffness and dexterity to name just a few of their benefits as opposed to their traditional serial counterparts. For the applications of parallel mechanisms in the field of sensor, previous work was focused on investigating the 6 degree-of-freedom force/torque sensors based on common Gough-Stewart platform. In this paper, a novel design of a multidimensional acceleration sensor is proposed based on 3RRPRR fully decoupling parallel elastic mechanism for kinetic information acquisition, specifically for measuring human motions. The translational elements of three perpendicular legs are served as elastic body which is manufactured by aluminum alloy. The detailed design of the structure is first introduced, followed by the mathematics modeling and performance evaluation. Finally, the finite-element analysis of resultant stress, strain and deformations is conducted based upon different input conditions to show the reliability of the proposed structure.