A negative-pressure needle knife comprises a negative-pressure extractor (1), an air pipe connector (2), a needle holder (3), a fastening screw (4), a needle knife (7), and a connecting sleeve (6). The negative-pressure extractor (1) is a bell-shaped outer casing, and an integrally formed cylindrical fixing sleeve (11) is vertically fixed to the top thereof. The bottom of the fixing sleeve (11) is inserted at the top of the negative-pressure extractor (1). The fixing sleeve (11) is sleeved on the needle holder (3). The aforesaid cylindrical connecting sleeve (6) is sleeved on the top of the fixing sleeve (11). The top of the connecting sleeve (6) is sleeved on the air pipe connector (2). The needle holder (3) is sleeved on the cylindrical needle knife (7). The lateral wall of the needle holder (3) is provided with the fastening screw (4) for fastening the needle knife (7). The lateral wall of the connecting sleeve (6) is provided with a vent hole (61). The air pipe connector (2) is connected with a negative-pressure machine. A negative-pressure space is formed by abutting the bottom of the negative-pressure extractor (1) against the human body. An acupuncture point is pierced using the needle knife (7). The invention thus resolves the technical issue of how to pierce an acupuncture point under negative-pressure using a needle knife.Un couteau-aiguille à pression négative comprend un extracteur à pression négative (1), un raccord de tuyau dair (2), un porte-aiguille (3), une vis de fixation (4), un couteau-aiguille (7), et un manchon de raccordement (6). Lextracteur à pression négative (1) est un boîtier externe en forme de cloche, et un manchon de fixation (11) cylindrique formé dun seul tenant est fixé verticalement à la partie supérieure de celui-ci. La partie basse du manchon de fixation (11) est insérée au sommet de lextracteur à pression négative (1). Le manchon de fixation (11) est emmanché sur le porte-aiguille (3). Le manchon de raccordement cylindrique (6)
