Belt conveyer checks the weight of the passing materials on weighting device in order to ensure the materials weight on tape; the digital speed measuring sensor installed on the tail continuously measures the operation speed of feeding device, the impulse output of the speed sensor is directly related to the speed of feeding device; the speed signal and weight sensor are sent to feeding device controller together, the microprocessor in controller deals with these signals and shows the integrating flow or instantaneous delivery. This flow rate is compared with set flow rate, control meter output signal controls belt conveyer and realizes the requirement of dosing. Belt conveyer is made up of frame, transmission belt, belt drum, tension device and driving device. The machine body is connected high quality steel plate and the height difference between front and rear supports forms the frame with a certain angle inclination in plane. Belt drum and carrier roller are installed on frame to drive and support transmission belt. The driving ways include reducing motor driving and motorized pulley driving.