The utility model discloses an electric power system tool to lock hole protection device, including components such as lids, spacer pin, spring, need not in the fix with screw just can install the lock body, it is rotatory around the lock core, realize that just, in the orientation that covers the lock core hole, this protection device has stop gear to the protection in lock core hole, guarantee that this protection device and tool to lock orientation are unanimously. The utility model discloses a simple structure, the installation is used conveniently, has played fine guard action to the lock core hole, avoids climbing into the influence to the tool to lock of small worm, spider etc. Has lengthened the life of tool to lock, has ensured normally opening of tool to lock, guarantees the normal running of electric power system equipment.