The invention relates to a transformer oil chromatography degassing device which comprises an oil storage tank. A heating system is arranged on the outer wall of the oil storage tank; high and low liquid level sensors are arranged in the oil storage tank; an oil drain pipe is lower than the low liquid level sensor and is connected with an oil drain pump; an oil inlet pipe is higher than the high liquid level sensor; a stirring pump is connected with two pipelines; and one pipeline is lower than the low liquid level sensor and the other pipeline is higher than the high liquid level sensor. Thetransformer oil chromatography degassing device is characterized in that a degassing pipe is higher than the high liquid level sensor; a pipeline external port is connected into a vacuum pump; the rear part of the vacuum pump is connected with a three-way piece; one end of the three-way piece is connected with an oil-gas separation component; the rear part of the oil-gas separation component is connected with a gas chamber; the rear end of the gas chamber is connected with a partitioning electromagnetic valve; a pressure sensor is connected in series between the gas chamber and the electromagnetic valve; the rear part of the partitioning electromagnetic valve is connected with a quantification ring; and another end of the three-way piece is connected with an external environment by an emptying electromagnetic valve. By the device, stability and accuracy of detection can be improved. The invention also provides a control method of the device, which can sufficiently separate gas in oil and improve safety, reliability and stability of the device.