The present invention discloses a secondary oil and gas
recovery device for a gas
station and an online
monitoring system thereof, comprising an oil gun, an
oil tank, and a
recovery device, wherein the oil gun and the
recovery device are both connected to the
oil tank, and a monitor is installed in the
oil tank to monitor the air pressure in the oil tank through the monitor; the recovery device comprises a condensation tank, an
air compressor, and a filter tank. In the present invention, the positive and negative rotations of the
air compressor can be controlled to form a corresponding linkage effect between a closing mechanism and a
discharge port. When the condensation tank is pressurized by the
air compressor, the closing mechanism and the
discharge port will close automatically, and there is no need for coordination through another mechanism, so that the space in the condensation tank can exist independently of the oil tank, so that the oil and gas recovery work will not affect the normal operation of the oil tank, and the air compressor can also be used to create a negative pressure in the condensation tank, to extract the air from the pump to the condensation tank, and to filter it through the filter tank, thereby effectively solving the technical problems raised in the background technology.