The invention discloses a ventilation functional element for a carbon nanotube reinforced ventilation channel in the field of refractory materials. The ventilation functional element comprises a ventilation functional element substrate, wherein the ventilation functional element substrate is provided with a ventilation channel; a carbon nanotube with a three-dimensional netlike structure is formed in the ventilation channel. The invention further relates to a preparation method for the ventilation functional element of the carbon nanotube reinforced ventilation channel. The preparation method comprises mixing, forming and sintering. Due to the adoption of the ventilation functional element for the carbon nanotube reinforced ventilation channel and the preparation method thereof, the problem of seepage of a metal liquid into a porous plug under the action of a static pressure in the prior art is solved on the premise of ensuring the gas flow of the ventilation functional element in unit time.