Aiming　at　the　spatial　incompleteness　problem　of　lacking　rotational　degrees　of　freedom　(RDOF)　in　traditional　joint　parameter　identification,　the　study　introduced　the　finite-difference　technique　to　estimate　the　rotation　angle　frequency　response.　In　order　to　depress　the　error　caused　by　the　modal　truncation,　the　experimental　data　of　frequency　response　was　regenerated　based　on　the　residual　compensation　theory.　The　measured　noises　can　be　eliminated　to　obtain　the　ideal　identification　results.　Taking　the　spindle-toolholder　joint　as　the　study　object,　the　frequency　responses　of　substructure　and　assembly　of　the　spindle-toolholder　system　can　be　obtained　by　the　hammer　peening　experiment.　The　structural　coupling　method　was　introduced　to　establish　the　stiffness　identification　model　of　dynamic　joint.　With　the　proposed　method,　the　dynamic　parameters　can　be　identified　exactly.　The　finite　element　model　was　established　to　verify　and　analyze　the　validity　of　the　identified　results.　The　results　of　the　comparison　experiment　and　the　simulation　show　that　the　proposed　method　can　exactly　identify　the　joint　parameters.