Abstract: Dry-type air-core reactors are widely used in China because of its simple structure,low price and basically maintenance free.However,due to the poor operating environment and its own quality,the burnout fault of dry-type reactor occur frequently,which seriously endangers the safety of equipment in substation.Most faults develop rapidly,and the reactor has been ablated or caught fire before the protection action.The existing protection configuration is difficult to quickly remove the fault protection reactor.Taking a 35 kV reactor burnout fault at the low voltage side of the transformer of a 500 kV substation as an example,by analyzing the protection action behavior and fault recording after the fault,the reason why the protection device can not quickly cut off the fault in the initial stage of the fault was clarified.Meanwhile,the protection configuration of dry-type air core reactor in the current engineering application was discussed,and the protective measures for the safe operation of the reactor were put forward.