The invention provides a method for high-efficiently carrying out oil draining and oiling during replacement of an oil-immersed transformer pipeline accessory. Exhaust valves of a cooling oil pump anda cooler system are used to drain oil from an oil-immersed transformer and accurate oil draining is achieved. A remaining oil storage space of an oil conservator is used to store discharged insulating oil so as to avoid problems of pollution of insulating oil and the like caused by external connection of an oil storage tank. Wastes of insulating oil during a work process are maximumly reduced andoil draining and oiling efficiency is greatly increased.