Negative pressure drainage device

The utility model discloses a negative pressure drainage device which comprises a negative pressure machine, a safety bottle and a drainage bottle. The negative pressure machine is connected with the safety bottle through a pipeline; the safety bottle is provided with a first pipeline, a pressure gauge and a pressure regulating valve; a second pipeline and a drainage tube are arranged on the drainage bottle, and the second pipeline is detachably connected with the first pipeline through a negative pressure suction connector at one end of the second pipeline; a sampling branch tube is arranged on the drainage tube, and scales are arranged on a bottle body of the drainage bottle. According to the negative pressure drainage device, adjustable negative pressure is achieved through the negative pressure machine, the safety bottle and the pressure adjusting valve on the safety bottle, and the negative pressure drainage device is suitable for drainage of different operations needing different negative pressures; the