Abstract: Incloseproximity，theservicingspacecraftisacomplexsystemwithrigidflexibleliquidcoupled，andtheliquidsloshingmodel，suchaspendulum，isn′tapplicable.Thedynamicsmodelingandcontrolofthisspacecraftwerestudied.Firstly，akindofnewliquidsloshingequivalentmechanicalmodelwasderivedbyvirtualworkprinciple，anditcouldbeappliedtothesituationoftriaxialthrust.Secondly，arelativepositionguidancevectorandarelativepositionerrorvectorweredefined，andarelativepositionerrordynamicsmodelwasderived.Thirdly，combiningtherelativepositionerrordynamicswiththerelativeattitude  dynamics，acoupledrelativeattitudeorbitdynamicsmodelwasestablished，whichwassuitablefortheprocessofcloseproximityinrendezvousanddocking.Themodelwasalsorigidflexibilityliquidcoupled.Finally，acontrollawbasedontheslidemodecontrolwasdesignedtoestimatetheunknownbutboundeddisturbances，systemuncertaintiesandmeasurementnoise.Theeffectivenessofthecontrollawwasvalidatedbynumericalsimulation.TheresultsofthesloshinginthesimulationagreewellwiththeFlow-3Dresults，whichindicatesthattheliquidsloshingequivalentmechanicalmodelisreasonable.

Key words: onorbitservicing, closeproximity, trajectoryguidance, rigidflexibleliquidcoupled, relativeattitudeorbitcoupled, slidingmodeestimator