Abstract: The structural clearance of flowmeter gets to increase due to wear after the flowmeter has been used in long service, even if the accuracy setter would not adjust the flowmeter to the specified accuracy range, therefore, overhauling the excessively worn flowmeter is very necessary in order to ensure its accuracy. The overhauling process of the flowmeter is introduced. Meanwhile, the repairing method and requirements for the major elements of flowmeter and the notice of overhauling have been given.