With three translational asymmetric parallel machine tool (3-2SPS) as the research object, the vibration model of single chain institutions is researched. The whole branched chain equivalent vibration model was deduced. A single chain and machine multidegree of freedom vibration system of differential equations of motion of the machine were established. Using the MATLAB software to multiple degrees of freedom of undamped vibration natural frequency, simulation analysis was carried out. Natural frequency of front two stages inside workspace of the machine tool is obtained, which provide reference for the subsequent optimization design of machine tool and production.