The oil immersed transformer has the advantages of low loss, low noise and high efficiency, which can achieve good energy-saving effect and reduce pollution. Compared with the ordinary oil immersed transformer, our company's transformer cancels the oil conservator, and the change of oil volume is automatically adjusted and compensated by the elasticity of the corrugated sheet of the corrugated oil tank. The transformer is isolated from the air, so as to prevent and slow down the deterioration of oil and insulation aging, enhance the operation reliability, and avoid maintenance in normal operation.