The invention discloses a kiln feeding system for directly injecting refuse-derived fuel into a cement kiln. The kiln feeding system comprises a pyrolyzing furnace with a high-position feeding port, a vertical continuous hoist, a horizontal continuous conveyor and a buffer bin, the vertical continuous hoist and the pyrolyzing furnace are adjacent to each other and are arranged side by side, a discharging port is formed in one upper side of the vertical continuous hoist and positioned above the feeding port of the pyrolyzing furnace, a feeding port is formed in the other side of the lower end of the vertical continuous hoist, a discharging port is formed in one end of the horizontal continuous conveyor and positioned above the feeding port of the vertical continuous hoist, a feeding port is formed in the other end of the horizontal continuous conveyor, the buffer bin is arranged above the feeding port of the horizontal continuous conveyor, and a feeding device is arranged at the bottom of the buffer bin. The kiln feeding system for directly injecting the refuse-derived fuel into the cement kiln is capable of improving conveying capacity of refuse-derived fuel greatly, and the occupied area of the kiln feeding system can be decreased greatly.