The invention relates to the technical field of feed. A feeding port is included. A positive plate is fixedly connected to the inner side of the feeding port, a negative plate is fixedly connected tothe position, close to the bottom of the positive plate, of the inner side of the feeding port, and a piezoresistor is fixedly connected to the position, close to the bottom of the negative plate, ofthe inner side of the feeding port. According to the anti-blocking feed grinder, the relative area of the positive plate and the negative plate is gradually reduced through movement of a dielectric plate, namely, the voltage in a circuit is reduced, when the maximum working voltage of the piezoresistor is reached, current passes through the circuit, a magnet moves under the action of repulsion, the rotating speed of a screw is gradually increased, and blocked feed is dredged; and normal use of the machine is guaranteed, the feed crushing efficiency is improved, meanwhile, the blocked feeding port does not need to be manually cleaned, when the machine works, a worker does not need to be on guard and does not need to observe the use condition of the machine, the feeding port can be cleaned in time, and manpower and time are saved.