This paper presents a study on the design and test a multiple-DOF motion platform for vibration analysis of heavy duty vehicle seat suspension. This motion platform is designed to have 6-DOF based on the mechanism of the parallel manipulator, which has high force-to-weight ratio, high dexterity and high accuracy of position. This platform can be utilized to accurately simulate vehicle vibration with x, y, z-axis translation and roll, pitch, yaw-axis rotation. The 6-DOF platform is first designed by the PTC Creo software, and then the 3D model is imported into SimMechanics to get a dynamics model for motion analysis and controller design. The vibration simulation of model shows the motion platform has a good trajectory tracking ability. After the design and simulation are successfully completed, a practical motion platform with 6 electrical cylinders is built. This motion platform is designed to support 250kg load and achieve a maximum vibration simulation frequency of 12Hz. The experiments prove that the motion platform can simulate the translation and rotation vibration with required frequency range and amplitude. This 6-DOF motion platform can be applied in the multi-DOF vibration analysis for heavy duty vehicle seat suspension.