Whole-grain-grade efficient dry coal preparation equipment and working method thereof

The invention discloses whole-grain-grade efficient dry coal preparation equipment and a working method thereof, and relates to the technical field of coal preparation equipment. The whole-grain-grade efficient dry coal preparation equipment comprises an external device, the external device comprises an external plate, a vibration groove is formed in the right upper side of the front surface of the external plate, a vibration bag is fixedly connected to the right interior of the vibration groove, a first spring is fixedly connected to the right inner wall of the vibration bag, a piston is fixedly connected to the left end of the first spring, the piston is in a T shape, the left end of the piston penetrates out of the outer side of the vibration bag, the piston is located inside the vibration groove, a coal preparation device is arranged in front of the external plate and comprises a first coal preparation box, a second coal preparation box is fixedly connected to the left side of the first coal preparation b