The invention discloses a tidal rage type manual downwelling device, and belongs to the technical field of marine anoxia. The tidal rage type manual downwelling device comprises an upper water storagetank, electromagnetic valves, downwelling vertical pipes, mixers and a lower drainage tank; the upper water storage tank is communicated with the lower drainage tank through at least one downwellingvertical pipe; one electromagnetic valve is arranged on each downwelling vertical pipe; the mixers are arranged on the inner side wall of the lower drainage tank; and the side wall of the lower drainage tank is provided with drain outlets. According to the tidal rage type manual downwelling device, the problem of seabed anoxia can be solved by utilizing the tidal range to generate downwelling; during the flood tide, the electromagnetic valves are closed, and the upper water storage tank stores water; after the tide ebbs and is static for a period of time, water in the upper water storage tankreaches the salinity close to that of bottom seawater after the evaporation temperature of the water in the upper water storage tank is increased, and then the electromagnetic valves are opened to form downwelling; and oxygen-enriched water in the upper water storage tank and anoxic water in the lower drainage tank are fully mixed under the action of the mixers and are discharged through the drainoutlets in the wall of the lower drainage tank, and the discharged oxygen-enriched water is mixed with the surrounding anoxic water so as to alleviate the anoxia problem under the sea.