The invention aims to effectively solve the problem of preventing material blockage of a thickener cone hopper, discloses a device for eliminating blockage in the thickener cone hopper, and belongs to the technical field of solid-liquid separation of mineral machining. The device is characterized in that a thickener lower part cone hopper is supported by a cone hopper support frame; a conical vibrating grid is independently supported or hung inside the thickener lower part cone hopper; a certain gap is formed between the periphery of the conical vibrating grid and inner walls of the thickener lower part cone hopper; a plurality of main beams of the vibrating grid support horizontally pass through a plurality of round holes formed on the thickener lower part cone hopper and are welded with the conical vibrating grid arranged in the thickener lower part cone hopper into a whole body; the vibrating grid support arranged on the two sides of the thickener lower part cone hopper is provided with a vibration source base; the vibration source base is provided with a vibration source; the whole body of a vibration support is fixed on a spring support frame by a spring to form an independent support structure or a suspension structure; and the vibrating grid support and the cone hopper are sealed by an elastic sealing gasket. In the device, the vibration source directly transmits vibration to the conical vibrating grid to loose materials in the cone hopper, and almost has no influence on the cone hopper.