As　the　core　module　of　serial-parallel　hybrid　machining　equipment,　the　driving　characteristics　of　parallel　manipulators　are　crucial　to　overall　system　performance.　A　set　of　index　is　proposed　to　evaluate　the　driving　characteristics　of　a　Z4　redundantly　actuated　parallel　manipulators.　Based　on　the　proposed　indices,　the　task　workspace　is　optimized　and　the　servo　torques　are　predicted.　First,　the　inverse　kinematics　of　a　Z4　parallel　manipulator　is　derived　with　closed-loop　vector　method　to　construct　a　nondimensional　Jacobian　matrix,　which　is　used　to　evaluate　kinematic　isotropy.　Second,　a　rigid-body　dynamic　model　is　established　by　using　Lagrange　method,　based　on　which　a　minimum　2-norm　is　formulated　to　allocate　driving　forces　between　different　limbs.　By　selecting　the　tooltip　as　a　reference　point,　a　set　of　isotropy　index　is　defined　in　terms　of　acceleration,　velocity,　and　dynamic　cutting　force　as　well　as　driving　torque.　Finally,　the　optimum　task　workspace　and　servo　torques　are　determined　based　on　the　proposed　indices.　A　simple　experimental　test　is　carried　out　to　validate　the　selected　servo-motors　meet　the　serving　requirements.　©　2024　Chinese　Mechanical　Engineering　Society.　All　rights　reserved.