Online PH value calibration device

The utility model relates to an on-line PH value calibration device, which is characterized in that a first end of an off-line monitoring pipeline is connected between a third pneumatic valve and a centrifugal pump, a second end of the off-line monitoring pipeline is connected with the end part of one side, far away from a stock solution tank, of a sixth pneumatic valve, and a seventh pneumatic valve, an off-line sampling groove and a second pneumatic valve are connected in series on the off-line monitoring pipeline; an off-line PH electrode is inserted into the off-line sampling groove, the off-line PH electrode is electrically connected with an off-line PH analyzer and the controller in sequence, the off-line sampling groove is further connected with an off-line PH electrode cleaning pipeline, the first end of the off-line PH electrode cleaning pipeline directly faces the off-line PH electrode in the off-line sampling groove, and the second end of the off-line PH electrode cleaning pipeline directly faces t