The utility model discloses a concrete admixture adding device. The device comprises a base and a storage tank, a storage tank is arranged above the base; a fixing frame is arranged at the upper end of the storage tank; a motor is mounted on the fixed frame; a rotating rod is mounted in the storage tank; the upper end of the rotating rod is connected with a rotating shaft of a motor through a storage tank; stirring blades are mounted on the rotating rod; a liquid conveying pipe is arranged below the side wall of the right end of the storage tank; the right end of the liquid conveying pipe is connected with a liquid conveying pump, a conveying pipe is installed at the upper end of the liquid conveying pump, a pressure sensor is arranged on the right side of the position, where the liquid conveying pump is located, of the base, a measuring cylinder is arranged above the pressure sensor, and the conveying pipe communicates with the upper portion of the side wall of the left end of the measuring cylinder. By arranging the measuring cylinder, the pressure sensor and the stirring blades, the problems that the concrete admixture is easy to precipitate and layer, and the accurate dosage ofthe admixture cannot be mastered are solved.