WDLB drop-out metal oxide surge arrester is applicable to power transmission and substation systems of 35kV and below. The product is elegantly integrated with the metal-oxide surge arrester with disconnector and the drop--out fuse. The arrester quickly turns and falls down to stop operation, and to prevent the system from single-phase fault. Moreover, the disconnection sign is obvious. It can also realize the live replacement of arrester when the disconnector of the arrester acts, that is, replace the damaged arrester in the case of uninterrupted power supply, improving the efficiency of overhaul and maintenance of power line. The product is widely used in Daqing Oilfield, Changqing Oilfield, Dagang Oilfield, Shengli Oilfield, Jianghan Oilfield and transmission and distribution systems. Featured by reliable protection performance and easy maintenance and overhaul, it has gained the enormous popularity of the users.