Based　on　the　pseudo-rigid-body　model　(PRBM),　a　PR　pseudo-rigid-body　dynamic　model　(PRBDM)　subjected　to　a　force　at　the　end　was　developed　considering　the　effects　of　transverse　deformation　and　axial　deformation　of　flexible　elements　in　compliant　mechanisms　comprehensively.　The　dynamic　equation　of　the　PR　PRBDM　was　derived　by　using　the　Lagrange　equation.　The　changes　of　performances　of　the　PR　PRBDM　were　showed　in　the　equation　feature　and　dynamic　responses.　The　numerical　analysis　results　indicate　that　the　PR　PRBDM　proposed　can　be　used　to　show　the　real　dynamic　characteristic　of　compliant　mechanisms　by　introducing　a　prismatic　pair　to　simulate　the　axial　movement　of　flexible　elements　in　compliant　mechanisms　and　was　suitable　for　the　dynamics　analysis　and　design　of　compliant　mechanisms.