The full-length trehalose synthase gene (Tres) was synthesized by genetic engineering and inserted into the Pichia expression vector pPICZα. The expression vector carrying Tres gene was transformed into the competent cells of Pichia GS115 by means of electroporation, and Zeocin resistance screening was then performed to find positive strains. PCR and gene sequencing were used to identify the expression of the target gene. The expressed protein was analyzed by SDS-PAGE and Western blotting. The results suggested that the recombinant plamid pPICZα-Tres was successfully constructed and that the target gene had been integrated into the Pichia genome.