The invention belongs to the technical field of medical equipment, and particularly relates to a closure device. The closure device comprises a sealing part and a fixing part, the fixing part comprises a plurality of supporting rods and at least one anchor thorn arranged on at least one supporting rod, a first end of each anchor thorn is fixed to the corresponding supporting rod, a second end of each anchor thorn faces the outside of the fixing part, wherein at least one anchor thorn is provided with at least one limiting piece, and the outer diameter of the part, located between the second end and the limiting piece, of the anchor thorn is smaller than that of the limiting piece. According to the closure device of the invention, at least one limiting piece is arranged on at least one anchor thorn, and the outer diameter of the part, located between the second end and the limiting piece, of the anchor thorn is smaller than that of the limiting piece, when the anchor thorn pierces the inner wall of the left auricle, the limiting piece on the anchor thorn can effectively limit the piercing depth of the anchor thorn, so that pericardial effusion and other problems caused by the situation that the anchor thorn pierces through the inner wall of the left auricle due to the excessively high piercing depth of the anchor thorn are solved, and the possibility of medical negligence is reduced.