A non-return device of a clip applier has a reciprocating rod located in the middle of a casting. A handle is pivoted on the casing, and a moving rod is pivoted between the reciprocating rod and the handle. A groove is formed in the casing, a ratchet is disposed on a sidewall of the groove, and a cam is disposed in a middle of the groove. A follower component is fixed on the reciprocating rod, and a flexible arm is extended by the follower component. A reaching ratchet and a reaching follower are disposed on the flexible arm and extended into the groove. The reciprocating rod drives the follower component and let the reaching follower moving around a surface of the cam so that the reaching ratchet slides on the ratchet and is able to avoid the reciprocating rod return in halfway while being moved forward.一種血管施夾器止逆裝置，是在一外殼的中間設有一可沿前後方向往復動作的往復桿，在該外殼樞接一握把，在該握把與該往復桿之間樞接一連桿，在該外殼的頂側設有一活動槽，在該活動槽的側壁設有一棘齒條，又在該活動槽內形成一凸輪，在該往復桿固設一滑塊，由該滑塊伸設一可彈性地側向擺動的延伸臂，在該延伸臂設有一滑動桿以及一伸入該活動槽的棘齒塊，當該往復桿往復動作而使該滑動桿循環繞行該凸輪時，該棘齒塊先齧合在該棘齒條單向滑動後再由該棘齒條退開，除了避免該往復桿往復動作時逆向以外，構造簡單而容易組裝。
