An automatic drainage device comprises a drainage container separated by a partition plate into a fluid storage cavity provided with a connecting pipe and a fluid discharge channel provided with a fluid discharge outlet. The partition plate is provided with a fluid drainage outlet that connects the fluid storage cavity to the fluid discharge channel. The device further comprises a movable gasket disposed below the partition plate for closing the fluid drainage outlet, and a control device comprising a remote control receiving module or a control device configured to monitor a liquid level in the fluid storage cavity, to move the movable gasket to open or close the fluid drainage outlet. The automatic drainage device remotely activates the control device by a remote control receiving module or by monitoring the status of the liquid level, to control the opening and closing of the fluid drainage outlet.
