An automatic conveying device includes a conveyer bracket, a wheel assembly, a transmission mechanism, and a loading assembly. The wheel assembly is rotatably assembled to a bottom portion of the conveyer bracket for supporting the conveyer bracket. The transmission mechanism is assembled within the conveyer bracket and connected with the wheel assembly, thereby driving the wheel assembly to rotate. The loading assembly is mounted upon the conveyer bracket and movably assembled with the transmission mechanism, for accepting objects as a load and driving the transmission mechanism to work. The loading assembly moves downward relative to the conveyer bracket under the weight of the objects placed on the loading assembly, and is capable of moving upward back to its original position, when the objects are removed.