The invention discloses an AaTSW2 gene promoter and a preparation method thereof. A nucleotide sequence of the promoter is shown as a first sequence in a sequence table. Meanwhile, the invention further relates to application of the AaTSW2 gene promoter in the genetic engineering breeding in which metabolic products are expressed and produced by means of glandular hair tissue of a plant. According to the AaTSW2 gene promoter and the application and preparation method thereof, the promoter can guide genes to be specifically expressed in a glandular hair of the plant, and due to the fact that the promoter which is specifically expressed in the glandular hair performs genetic manipulation on a glandular hair system of the plant, harm cannot be caused to the growth and development of the plant; accordingly, the important significance is achieved for genetic engineering breeding in which the metabolic products are expressed and produced by means of the glandular hair tissue of the plant.