The invention discloses a decontamination tool for an inservice inspection device of a rod cluster control assembly. The decontamination tool comprises a lift ring, a planet carrier, a connection rod and a decontamination rod. The decontamination rod is hollow and divided into a wiping section and a washing section from top to bottom, wherein wiping sponge is arranged on the wiping section in a sleeving mode, and a water outlet is formed in the lateral wall of the washing section. The decontamination tool further comprises a water pump. After once auxiliary centering of a worker, the decontamination tool for the inservice inspection device of the rod cluster control assembly can clean an ultrasonic probe hole, an eddy current probe hole, an encoder roller and a centering device in two modes of wiping and low-pressure water flushing and can decontaminate pollutant like high-dose ash on all radiation hot spot positions in distance. Compared with manual decontamination, the decontamination methods of wiping decontamination and water flushing decontamination can greatly reduce near operation time of workers, are higher in decontamination level and greatly reduces collective dose bored by worker during following-up assembling and disassembling, transportation, maintenance and another inspection of equipment.