A closed type drainage device for thoracic cavity, comprising a drainage catheter (16), a first vent tube (14), a storage bag (1) and a measuring bottle (2) fixed on an outer side of the storage bag (1) a measuring cavity (3) and an observation cavity (9) are disposed in the measuring bottle (2) an end of the drainage catheter (16) extends from the top of the measuring bottle (2) into the measuring cavity (3) and is in communication with the measuring cavity (3) two ends of the first vent tube (14) extend from the top of the measuring bottle (2) into the measuring cavity (3) and the observation cavity (9) respectively a second vent tube (13), a first liquid inlet (15) and a second liquid inlet (17) are fixedly provided on the top of the measuring bottle (2) a water seal tube (11) is fixedly connected to an end of the first vent tube (14) a first uni-directional device (12) leading to the interior of the storage bag (1) is disposed on an end of the second vent tube (13) away from the observation cavity (9) a vent valve (10) in communication with the interior of the storage bag (1) is fixedly provided on an upper portion of the outer side of the storage bag (1) an outflow tube (4) in communication with the measuring cavity (3) is fixedly provided at the bottom of the measuring bottle (2) a second uni-directional device (7) leading to the interior of the storage bag (1) is disposed on an end of the outflow tube (4) away from the measuring cavity (3) the device has the benefit of reducing complications such as pneumothorax and the like, caused by air from outside entering a thoracic cavity via a drainage device.Linvention concerne un dispositif de drainage de type fermé pour une cavité thoracique, comprenant un cathéter de drainage (16), un premier tube daération (14), un sac de stockage (1) et une bouteille de mesure (2) fixée sur un côté extérieur du sac de stockage (1) une cavité de mesure (3) et une cavité dobservation (9) sont disposées dans la bouteille de mesure
