Pretreatment device and pretreatment method for transformer oil

The invention provides a pretreatment device and a pretreatment method for transformer oil. The pretreatment device comprises an electromagnetic valve, a ball valve, an oil tank, an oil cylinder, a circulating pump, a vacuum pump, an oil-gas separation chamber, a pressure sensor, a stepping motor, an air and nitrogen interface, an oil inlet and an oil outlet, wherein the oil inlet is connected with the oil tank, the oil cylinder and the circulating pump through four-way pieces, the oil cylinder is respectively connected with the oil tank, the oil-gas separation chamber and the pressure sensor, the ball valve is arranged between the oil tank and the oil cylinder, a piston of the oil cylinder is fixedly connected with the stepping motor through a mechanical device, the bottom of the piston is connected with the oil outlet, and the oil-gas separation chamber is connected with the air and nitrogen interface, and connected with the vacuum pump through the electromagnetic valve. According to the pretreatment device and the pretreatment method, the transformer oil is pretreated by introducing three degassing methods such as vacuum atomization degassing, air cleaning and nitrogen cleaning, so that the deficiency of cleaning and degassing effects of various methods can be made up, and residual gases dissolved in original transformer oil can be eluted efficiently.