Wheat endoplasmic reticulum oxidoreductin 1 (wEro1) was expressed by Pichia pastoris recombinant to develop a healthy and natural novel biological flour improver． The wero1 gene was subcloned into the Pichia pastoris expression vector pPICZα A，and the secretory expression of wEro1 was realized in Pichia pastoris GS115． The yield of wEro1 reached (53. 24 ± 2. 11)U/mL after optimizing the induced expression conditions． The expressed products were purified by ammonium sulfate precipitation and anion exchange chromatography，and the enzymatic properties of wEro1 were investigated． The reasults show that wEro1 possesses thiol oxidizing activity catalyzing disulfide isomerase (PDI) with an optimum pH of 7. 5 and an optimum temperature of 30℃; the enzyme has good stability under low temperature and neutral pH conditions． Pichia pastoris recombinant wEro1 was added to flour to investigate its effect on flour processing quality． It was found that the ability of Pichia pastoris recombinant wEro1 to improve flour silty properties was stronger than that of E. coli recombinant wEro1．