Abstract: At present, more than 95% of the distribution transformers put into operation in the power system are 10 kV oil immersed fully sealed transformers with model S9-S11; YW series tubular oil level indicator is adopted for this kind of transformer. The indicator has no oil storage and rainproof skirt, which can not timely ensure that the transformer oil tank is often full of oil and moisture-proof. Its design defect has become one of the main factors for a large number of burnout of 10 kV distribution transformer; Through the research on the multi-functional and universal tank oil storage and pressure relief oil level indicator of distribution transformer, it is of great significance to improve the safe operation stability of power system distribution transformer and reduce the burning risk of distribution transformer.