In　order　to　make　the　valveless　piezoelectric　pump　with　Y-shape　tubes　meet　well　with　the　needs　of　transporting　blood　and　fluid　in　such　areas　as　medical　treatment　and　sanitation,　theoretical　analysis　are　applied　to　the　pump　and　the　governing　equations　of　the　pump　are　established,　and　the　finite　element　method　is　employed　to　simulate　the　fluid　flowing　state　in　Y-shape　tube　and　the　whole　pump.　The　pressure　loss　coefficients　derived　from　the　simulation　results　show　a　little　difference　from　the　experimental　data,　thus　the　correctness　of　the　simulation　is　proved.　The　simulation　results　reveal　that　the　pressure　in　the　pump　chamber　varies　calmly,　and　the　pressure　in　the　tubes　eases　off　when　the　separation　angel　of　two　branch　tubes　increases,　and　there　exists　small　vortex　area　at　the　intersections　of　the　tubes　and　the　pump　chamber.　Therefore,　larger　separation　angel　of　two　branch　tubes　should　be　employed　and　round　corner　should　be　made　at　the　intersections　of　the　tubes　and　the　chamber　during　the　process　of　making　valveless　piezoelectric　pump　with　Y-shape　tubes　to　decrease　the　votex　in　the　pump.