Disclosed is an anti-drip plug-free negative pressure drainage system, comprising a suction tank (320) and a negative pressure device (340). A cover (310) is arranged at the top of the suction tank. A suction bag (300) is arranged in an inner cavity of the suction tank. A connector (312) is arranged in the center of the top of the cover, and the other end of the connector is arranged in the inner cavity of the suction tank to be connected to an interface (313). The negative pressure device is connected to a negative pressure source interface (315) in the inner cavity of the suction tank by means of a connecting pipe. The suction tank consists of a tank mouth section (320-2) and a tapered accommodating cavity section (320-6). The interface consists of the cover, a column-type on-off valve (313-2), a retaining bar (313-3), a limiting assembly (313-4) and a first spring (313-5), wherein same are assembled together. The connector consists of a 90-degree connector (312-6), a fixed end (312-7), an elastic sealing plug (312-9), a valve element (312-10) and a second spring (312-11), wherein same are assembled together. A locating slot on the connector is mounted in a circular locating hole on the interface in a clockwise rotating manner. The negative pressure drainage system realizes anti-drip and plug-free functions by means of its own structural design, and has the advantages of convenient mounting and reliable connection at the same time.L'invention concerne un système de drainage à pression négative sans bouchon anti-goutte, comprenant un réservoir d'aspiration (320) et un dispositif de pression négative (340). Un couvercle (310) est disposé au niveau de la partie supérieure du réservoir d'aspiration. Un sac d'aspiration (300) est disposé dans une cavité interne du réservoir d'aspiration. Un connecteur (312) est disposé au centre de la partie supérieure du couvercle, et l'autre extrémité du connecteur est disposée dans la cavité interne du réservoir d'aspiration en vue
