The invention provides a drainage device. The drainage device comprises a drainage container provided with a liquid storage cavity, wherein a liquid inlet is arranged in the liquid storage cavity, ora liquid inlet and a liquid drain outlet are arranged on the liquid storage cavity; the drainage container is further provided with a monitoring device capable of monitoring liquid pressure of drainage liquid on the liquid inlet. The drainage device can monitor liquid pressure data of the drainage liquid, the precision is high, meanwhile, the artificial manual operation is not needed during the monitoring process, the monitoring condition can be accurately recorded, the design of the liquid inlet capable of being opened and closed is matched, so that the functions of the bladder of a patient can be effectively protected, the labor intensity of nursing staff can be reduced, and the medical safety is guaranteed. The drainage device is applied to the field of medical apparatus and instruments.