The invention discloses a lithium carbonate carbonic acid hydrogenation device. The lithium carbonate carbonic acid hydrogenation device comprises a device box, a lithium hydrogencarbonate collectingtank and cooling holes are formed in one side of the device box, a lithium carbonate storage tank, a water tank and a precipitator storage box are arranged at the top of the device box, a device box baseboard is arranged at the bottom of the device box, fixed bolts, a driving motor and a carbon dioxide storage tank are arranged at the top of the device box baseboard, a concentration sensor is arranged at one side of the carbon dioxide storage tank, a connecting pipe is arranged at the other side of the carbon dioxide storage tank, a reaction tank is arranged at one end of the connecting pipe,a discharging opening is formed in one side of the reaction tank, a precipitator inlet, a water inlet and a lithium carbonate inlet are formed in the top of the reaction tank, a reaction tank cavity is formed inside the reaction tank, a stirring shaft is arranged at the bottom of the reaction tank cavity, a stirring plate and stirring blades are arranged on the outer surface of the stirring shaft.Therefore, by means of the lithium carbonate carbonic acid hydrogenation device, the problem of deposition of lithium carbonate is solved through the stirring shaft and the stirring blades.