Based　on　the　job　site　condition　of　shaft　lining　sinking　by　means　of　floatation,　model　experiment　equipments　of　drilling　shaft　lining　and　experimental　process　were　designed,　then　the　sinking　by　means　of　floatation　experiment　was　finished.　The　results　show　that　the　deflection　cure　of　cylinder　shaft　lining　is　roughly　sine　cure　when　uplouted　prevention　second　balance　weight　water　is　filled　after　lowering　it　to　bottom　of　a　shaft　hole.　At　the　same　time,　the　opposite　force　in　shaft　top　facing　bars　would　be　increasing　as　the　increase　of　shaft　wall　inner　force.　The　experiment　results　indicate　that　the　slipping　of　a　shaft　pan　is　caused　by　adding　second　weight　water.