A ligation device comprises a clamp(1) and a conveying unit(2). The clamp(1) comprises a clip(11) and a tightening tube(12) to tighten a rear end of the clip(11) therein, the clip(11) comprises two clamping arms(111;112). The conveying unit(2) comprises a traction line(21), a conveying tube(22) and a control handle(23), the traction line(21) runs through the conveying tube(22), the control handle(23) is connected with a rear end of the conveying tube(22) and a rear end of the traction line(21) to drive the traction line(21) to operate the clamp(1). At least one bearing piece(113) is arranged at a tail of the clip(11) and can be deformed or broken under a certain pressure, the bearing piece(113) is assembled to form a hole(114), the traction line(21) runs through the hole(114) and a front end of the traction line(21) is blocked by the bearing piece(113), when the clamp(1) is released, the bearing piece(113) is deformed or broken under force exerted by the front end of the traction line(21) so that the clamp(1) is disengaged from the conveying unit(2).