The invention discloses a concrete mixing device, comprising box bodies arranged symmetrically up and down, wherein a symmetric fixing support rod is arranged between the box bodies, and fixes the boxbodies on the upper and lower sides; transmission cavities are disposed in the box bodies, and symmetrical inner cavities disposed in the box bodies are arranged on two sides of the transmission cavities; the inner cavities are arranged in a vertical penetrating manner, and are provided with processing devices for containing sand gravel and cement for processing into concrete; the processing devices are driven by a power device disposed between the transmission cavities. The concrete mixing device has a simple structure, can push while stirring the sand gravel and cement to improve the preparation effect of concrete; the structural design that is convenient for personnel to disassemble and install is utilized, so that the personnel can conveniently clean the device, and the cleaning burden is reduced.