Automatic gas taking device and method for transformer

The invention discloses an automatic gas taking device and method for a transformer. The device comprises a gas taking box, a control module and a waste oil box. The gas taking box is connected with the gas relay and the gas collecting bag through a gas taking electromagnetic valve and an exhaust electromagnetic valve respectively and is used for taking and exhausting gas of the gas relay based on the first liquid level sensor, and the gas exhausted by the gas taking box is collected through the gas collecting bag; the waste oil box is connected with the gas taking box through an oil discharge electromagnetic valve and is used for collecting and discharging oil in the gas taking box based on a second liquid level sensor; and the control module is used for controlling the gas exhausting, gas taking and oil discharging processes of the whole device. Gas can be automatically taken and stored, the gas content in the gas collecting bag can be monitored in real time, the gas taking process is automatically triggere