Building material mixing device

The utility model discloses a building material mixing device which comprises a stirring shaft, a stirring rod and a stirring box, the top end of the stirring shaft penetrates through a bottom plate of the stirring box and extends into the stirring box, the stirring shaft is connected with the stirring box through a speed reducer installed at the bottom of the stirring shaft, and the interior of the stirring shaft is hollow. A rotating mechanism is arranged at the bottom of the stirring shaft and comprises an eccentric ball, four hoses are fixedly connected to the surface of the eccentric ball, a solid ball is fixedly connected to one end of each hose, the four hoses are uniformly arranged from top to bottom relative to the surface of the eccentric ball, the surface of the solid ball is movably connected with a stirring rod through a supporting rod, and a universal bearing is fixedly connected to the inner top wall of the eccentric ball. The inner ring of the universal bearing is fixedly connected with a cent