Downward belt conveyor is a special rubber conveyor delivering materials from high to low, this rubber conveyor shows negative power, enabling motor to be in the dynamic braking state. Effective control for full-load start and stop of belt conveyor, especially realization of controllable soft brake of rubber conveyor in the case of sudden loss of power to prevent runaway of rubber conveyor is a key technique in this rubber conveyor. As of now our company has designed, manufactured and installed multiple downward belt conveyors for enterprises including Sichun Dayunhe, Pingliang Hailuo and Changxing Mining, etc. The figure below shows a 4021m long downward belt conveyor for Pubugou to convey materials for casting dam of Pubugou Hydropower Station.