Closed-form solutions were developed to optimize kinematics design of a 2-degree-of-freedom (2-DOF) planar parallel manipulator. The optimum design based on the workspace was presented. Meanwhile,a global, comprehensive conditioning index was introduced to evaluate the kinematic designs. The optimal parallel manipulator is incorporated into a 5-DOF hybrid machine tool which includes a 2-DOF rotational milling head and a long movement worktable. The results show that the planar parallel manipulator-based machine tool can be successfully used to machine blades and guide vanes for a hydraulic turbine.