An exemplary method for fabricating a carbon nanotube-based field emission device is provided. A substrate is provided. A catalyst layer is formed on the substrate. A carbon nanotube array is grown from the catalyst layer. The carbon nanotube array includes a root portion and an opposite top portion respectively being in contact with and away from the catalyst layer. A cathode base with an adhesive layer formed thereon is provided. The top portion of the carbon nanotube array is immersed into the adhesive layer. The adhesive layer is solidified to embed the immersed top portion into the solidified adhesive layer. The root portion of the carbon nanotube array is exposed.