The invention relates to the technical field of phosphoric acid storage equipment, in particular to a device capable of timely and conveniently cleaning scale on the tube wall of a phosphoric acid storage tank. The device comprises a spiral reamer, a spiral cutter shaft, a lead screw support and a lead screw, the spiral reamer is driven to rotatably walk into a pipeline of a connecting pipe on an acid outlet of a phosphoric acid storage tank by rotating the lead screw, and in the walking process of the spiral reamer, the scale accumulated on the inner side of the tube wall and a valve is cut into pieces and cleaned; when the lead screw is rotated oppositely, the spiral reamer is taken away from the connecting pipe. The device can be used at regular time to clean the scale on the pipeline on the acid outlet of the phosphoric acid storage tank and the inner wall of the valve, phosphoric acid raw material in the phosphoric acid storage tank does not need to be drained out fully, the problem that the production loads of an enrichment facility are affected because the pipeline on the acid outlet of the phosphoric acid storage tank and the valve are scaled is solved, time and labor are saved, raw material is saved, and production cost is lowered.