The invention provides an oil-immersed transformer oiling device, belonging to the technical field of oiling devices. The oil-immersed transformer oiling device aims to solve the technical problems of degassing, impurity removal and oiling in the insulating oil for transformers. The oil-immersed transformer oiling device comprises an oil drum, an oil level detection mechanism, an oil pump, an oil filter, an oiling tube mechanism and a control system, wherein the oil level detection mechanism is installed in the oil drum; the upper end of the oil drum is provided with an alarm lamp; one end of the oil pump communicates with the oil drum, and the other end communicates with the oil filter; the oil filter comprises a heating mechanism, a degassing mechanism, an impurity removal mechanism and a power mechanism; the oiling tube mechanism comprises an oiling tube and an exhaust tube; and the outer end of the oiling tube is fixedly provided with an adjustable flange. The oil-immersed transformer oiling device effectively performs impurity removal, degassing treatment and oiling before oiling of the oil-immersed transformer insulating oil, prevents the insulating property of the insulating oil for transformers from degradation due to the influence of gases and impurities, and obviously enhances the safety performance of the insulating oil for transformers.