SF 6 in the faulty gas insulation equipment can be resolved into low-fluoride sulfide under the effect of high energy. Some of them such as SF 2 , S 2 F 2 , SF 4 , SOF 2 , SOF 4 are easy to take hydrolysis and alkaline reactions, and some such as SO 2 F 2 , are able to occur partially alkaline reactions, and some are almost impossible to decompose such as S 2 F 10 , S 2 F 10 O and so on. The total amount of low-fluoride sulfide which can undergo hydrolysis and alkaline reactions in SF 6 could be determined by hydrolysis fluoride. Therefore, if the content of hydrolyzable fluoride is found to be significantly higher than its initial value, some internal faults may exist in the equipment. In addition, hydrolyzable fluoride in SF 6 will lead to the corrosion and accelerate deterioration of equipment and solid insulation materials. The amount of hydrolyzable fluoride represents the degree of toxicity, which is one of the important indicators of the quality control of SF 6 . In this paper, the amount of hydrolyzable fluoride in SF 6 is determined by the ion chromatography. The variation tendencies of hydrolyzable fluoride are investigated under discharge and overheating conditions and the content of hydrolyzable fluoride in SF 6 in normal and failure conditions is compared. In this paper, the traditional method is improved by simplifying the absorption method of the lye absorption step and adopting mechanical oscillation absorption, which make the absorption effect is controllable, the automatic drawing by the ion chromatography workstation in the standard working curve drawing step, which makes the operation easier. In the end, a reference value related to hydrolyzable fluoride for fault diagnosis is proposed, which has a certain reference significance for judging the fault condition in SF 6 equipment.