This paper introduces the phenomena of the fired fault and damage of a 35 kV dry-type reactor in 500 kV substation.Based disassembling the reactor and combining with the protection acting information as well as fault wave chart

the fault reasons are analyzed.And it is determined that the problems are due to the design（installation position）

manufacture technics and raw materials of the adjustable loop.Aiming to the problems of such fault

some anti-fault measures are given through aspects such as selection and installation position of the adjustable loop

the technical research of on-line temperature measuring and short circuit protection.It has certain reference value to the dry-type reactor safe operation.