The　surface　quality　of　polyurethane　pad　attached　to　the　polishing　tool　is　of　great　importance　to　the　polishing　performance,　and　it　is　usually　maintained　by　a　dressing　process.　In　this　study,　in　order　to　improve　the　pad　dressing　quality,　optimization　of　motion　control　during　the　dressing　process　is　presented,　from　the　aspects　of　the　uniformity　of　the　particle　trajectories　on　the　pad　and　the　consistency　of　the　relative　velocity　of　each　point　on　the　dressed　surface.　First,　kinematic　modeling　of　the　particles　on　the　dressing　tool　based　on　multibody　theory　was　proposed,　which　expresses　the　particle　trajectories　as　a　function　of　the　key　motion　parameters　n(g)　and　n(b).　Subsequently,　with　the　above　model,　simulations　were　conducted　to　find　the　optimized　range　of　n(g)　and　n(b).　The　results　have　shown　that　the　particle　trajectories　do　not　distribute　uniformly　while　n(g)　=　n(b),　and　along　with　the　increase　in　the　difference　between　n(g)　and　n(b),　the　uniformity　of　the　particle　trajectories　would　improve.　After　that,　to　further　optimize　these　motions,　the　relative　velocity　of　each　point　on　the　dressed　surface　that　involves　n(g)　and　n(b)　was　calculated　and　compared.　The　results　indicated　that　only　if　n(g)　＞　n(b)　are　the　consistencies　of　the　relative　velocity　of　various　points　on　the　dressed　surface　preferred.　Consequently,　n(g)　＞　n(b)　is　the　premise　to　satisfy　both　the　particle　trajectories　and　the　relative　velocity.　Furthermore,　by　considering　the　limitation　of　the　dressing　machine　and　dressing　efficiency,　the　optimized　ranges　for　n(g)　and　n(b)　are　500-1000　and　100-200　r/min,　respectively.　Finally,　experimental　validation　was　conducted　and　the　result　agreed　well　with　the　above　conclusion,　which　proved　the　optimization　of　the　motions.　[GRAPHICS]　.