The present invention belongs to the field of veterinary medicines, and specifically discloses poultry transfer factor nanoparticles and a preparation method thereof. The nanoparticles are made from the following raw materials by weight: 0.1-0.3% of poultry transfer factor, 0.6-2.6% of a carrier, 0.5-3% of a stabilizer, 0.6-1% of a surfactant, and 94-99.4% of water. After the stabilizer and the surfactant are completely dissolved in water, the poultry transfer factor is added, the pH value is adjusted to 3-4, n-butylcyanoacrylate is added under magnetic stirring, the stirring continues for 5-12h, the pH value is adjusted to 6-10, and a pale yellow transfer factor nanoparticle colloidal solution is obtained. The prepared solution is filtered with membrane and subsequently freeze-dried to prepare a freeze-drying powder under the condition of a temperature from -40 to -70 DEG C. The poultry transfer factor encapsulated by nanoparticles can prevent being degraded by pepsin, is conductive to intestinal absorption, can improve the stability of the poultry transfer factor, deliver drug targetedly, release drugs slowly, extend the time of drug action, and improve the bioavailability of the poultry transfer factor, and solves the shortcoming of low efficacy of oral transfer factor.