The invention relates to a disassembling and assembling tool of an isolating valve body sealing assembly and an overhaul disassembling and assembling process. A supporting part is matched with a valve body, a lifting lead screw and a valve deck are connected, and the valve deck is evenly lifted under rotation action of a fastening nut until the valve deck is separated from the valve body. The disassembling and assembling tool of the isolating valve body sealing assembly and the overhaul disassembling and assembling process can ensure rapidness and convenience of the overhaul disassembling and assembling process, parts can be well protected in the process and prevented from being damaged, assembling consistency before and after disassembly and assembly is ensured, the disassembling and assembling efficiency is improved, the overhaul risk is reduced, and the overhaul cost is saved.