The　piston　of　labyrinth　reciprocating　compressor　is　often　in　the　eccentric　running　state　during　operation,　which　leading　to　serious　gas　leakage　and　reduced　compressor　volume　efficiency.　To　optimize　the　performance　of　labyrinth　reciprocating　compressor,　the　main　reasons　of　piston　eccentric　operation　are　analyzed　in　detail　in　this　paper.　Based　on　the　theory　of　multi-body　dynamic　and　influence　of　piston　bending　and　vibration,　a　rigid-flexible　coupling　multi-body　virtual　simulation　model　of　piston/piston　rod　assembly　is　established　by　using　numerical　analysis　software.　The　factors　causing　eccentric　running　of　piston　in　cylinder　are　investigated　and　the　eccentric　running　track　of　piston　in　cylinder　and　its　dynamic　characteristics　are　obtained.　©　Published　under　licence　by　IOP　Publishing　Ltd.