The utility model discloses a reation kettle is used in water -based ink processing, including setting up the reation kettle body on the support, its characterized in that, this reation kettle this internal vertical the top of reation kettle body is equipped with the feed inlet to having agitating unit, the lateral wall of reation kettle body is equipped with oil -out and oil return opening respectively in top and bottom, connects oil -out and oil return opening through returning oil pipe, is equipped with oil drain pump on time oil pipe, the oil pipe that returns through increasing improves agitating unit simultaneously, improves reation kettle's reaction effect, improves the quality of printing ink.