The invention provides a cone yarn dyeing machine which comprises a cylinder body, a door, a liquid inlet, a liquid outlet and a yarn rack. The liquid inlet is formed in the bottom of the cylinder body. The liquid outlet is formed in the wall of the cylinder body. The yarn rack comprises a round base plate, a plurality of cone yarn sleeves and a rotating shaft. A plurality of liquid input holes are formed in the round base plate uniformly. The cone yarn sleeves are arranged on the round base plate uniformly. The cone yarn sleeves are hollow cylinder pipes. A plurality of penetrating liquid output holes are formed in the cone yarn sleeves. The bottom ends of the cone yarn sleeves penetrate out of the round base plate. The top ends of the cone yarn sleeves are closed ends, and the bottom ends of the cone yarn sleeves are open ends. One end of the rotating shaft is connected with a motor arranged at the outer top of the cylinder body, and the other end of the rotating shaft penetrates through the round base plate and is movably connected with the bottom of the cylinder body. The diameter of the round base plate is matched with the diameter of the cross section of the cylinder body. The cone yarn dyeing machine is good in yarn dyeing uniformity, high in dyeing efficiency and good in economic benefit.