A left atrial appendage occluder comprises a closure member (21), a fixing member (22) disposed at the distal end of the closure member (21), and a connecting member (23) for connecting the closure member (21) and the fixing member (22). The closure member (21) comprises a frame (215) and a cover (212) on the frame (215). The frame (215) comprises a proximal end face at least covered by the cover (212), and a supporting circumferential surface connected to the proximal end face and extending toward the distal end. The fixing member (22) is a cylindrical braided structure and the connecting member (23) is a flexible connecting member. After the fixing member (22) of said left atrial appendage occluder is placed at a corresponding position in the left atrial appendage, it deforms to adapt to the irregular shape of the chamber wall and the friction between the occluder and the chamber walls increases, causing it to be stably arranged inside the chamber. Harm to the chamber walls is eliminated due to there being no need to arrange an anchoring hook to secure the occluder.L'invention concerne un dispositif de fermeture d'appendice auriculaire gauche qui comprend un élément de fermeture (21), un élément de fixation (21) disposé au niveau de l'extrémité distale de l'élément de fermeture (21), et un élément de liaison (23) pour relier l'élément de fermeture (21) et l'élément de fixation (22). L'élément de fermeture (21) comprend un cadre (215) et un couvercle (212) sur le cadre (215). Le cadre (215) comprend une face d'extrémité proximale au moins recouverte par le couvercle (212), et une surface circonférentielle de support reliée à la face d'extrémité proximale et s'étendant vers l'extrémité distale. L'élément de fixation (22) est une structure tressée cylindrique et l'élément de liaison (23) est un élément de liaison souple. Une fois que l'élément de fixation (22) dudit dispositif de fermeture d'appendice auriculaire gauche est placé dans une position correspondante dans
