The utility model discloses a tube feeding device which comprises a plurality of sliding rails and switch devices. The sliding rails are arranged in an inclined mode, and the switch devices are arranged at the lower ends of the sliding rails and used for closing and opening the sliding rails. Each sliding rail comprises two rail bodies, wherein the spacing between the two rail bodies is larger than the tube diameter of blood sampling tubes and smaller than the diameter of vacuum blood sampling tube covers. According to the tube feeding device, the multiple sliding rails arranged in the inclined mode are adopted, the blood sampling tubes are placed on the different sliding rails according to different colors of the covers, and the blood sampling tubes are in suspension states and can downwards slide along the sliding rails under the effect of the gravity. The switch devices are arranged at the lower ends of the sliding rails and can control the sliding rails to be closed and opened; when the sliding rails are closed, the blood sampling tubes on the sliding rails are blocked with the switch devices and suspended on the sliding rails; when the sliding rails are opened, the blood sampling tubes can downwards slide along the sliding rails under the effect of the gravity and leave the sliding rails. The required blood sampling tubes with the covers with certain colors can be sorted by controlling the different switch devices on the sliding rails to be opened or closed.