The utility model discloses an improved concrete mixing device, which comprises a mixing barrel. The improved concrete mixing device is characterized in that one end of the mixing barrel is connected with a speed reducer and a motor through a connecting shaft, and the other end of the connecting shaft is connected with a mixing blade; the mixing blade is arranged in the mixing barrel, and a water content testing instrument is arranged on the inner wall of the mixing barrel; the mixing barrel is fixedly arranged on a rack; and the rack is connected with a support through a control device. The improved concrete mixing device has the advantages that the water content of concrete in the mixing barrel can be measured at any time; the workability change of the mixed concrete is small, and the quality of concrete is high; and the degree of automation of concrete mixing is high, the concrete mixing is uniform, and the concrete discharge is simple.