A device for 3D printing and a control method thereof are provided. The device includes: a feeding pipe, where an opening extending along an axial direction of the feeding pipe is disposed on an outer wall of the feeding pipe; and a sleeve sleeved on the feeding pipe, where a discharge port in communication with the opening is disposed on an outer wall of the sleeve. Compared with a conventional design, the above device utilizes a sleeve to provide a discharge port and sleeves the sleeve and the feeding pipe together, thereby making the structure of the entire device more compact.