The utility model provides a fully-enclosed dust-free feeding device which can be used for effectively reducing the amount of dust. The fully enclosed dust-free feeding device comprises a rack, supporting seats, a housing, a chain, chain wheels, feeding hoppers, a discharging hopper, a filter sieve, a side extension supporting arm, a conveying belt and a motor. The fully-enclosed dust-free feeding device adopts an enclosed feeding structure, and the enclosed feeding structure is vertical, so that the occupied space is relatively small, and the operation can be realized in a narrow work environment; the whole structure is simple, and the feeding stability in a using process is high; an enclosed feeding manner is adopted, so that not too much raised dust is generated in the using process, and the environmental pollution is effectively controlled; as the occupied space of the vertical structure is relatively small, the effective area of the fully-enclosed dust-free feeding device is also enlarged greatly.