The invention discloses an engineering bacterium for producing human stomach ethanol dehydrogenase (ADH) and a preparation method of the ADH of the engineering bacterium, and belongs to the technical field of biology. According to the engineering bacterium, a target gene is synthesized according to a gene sequence of the human stomach delta delta-ADH in a gene bank, and the target gene is connected with an expression vector pET-32a (+) and converted into E.coli BL21 (DE3). The preparation method comprises the steps that the E.coli BL21 (DE3) is induced by isopropylthio-beta-D-galactoside (IPTG) to express target protein existing in the form of inclusion bodies; thalluses are collected, crushed and centrifugalized, sediment is taken for obtaining the inclusion bodies, and a low-concentration urea solution or any of other buffer solutions is utilized for dissolving the inclusion bodies to obtain activated crude delta delta-ADH fluid; and the target protein is obtained by purifying HisTrapexcel through affinity chromatographic columns, and the activity of the protein is 2.085 U/mg or over. By adoption of the delta delta-ADH produced by the engineering bacterium provided by the invention, high-concentration ethyl alcohol can be oxidized, and the delta delta-ADH exists in escherichia coli in the form of the inclusion bodies; the activated crude delta delta-ADH fluid can be obtained simply by dissolving the inclusion bodies through the dissolving solution, renaturation is not needed, the cost can be lowered, the operating steps can be simplified, and the efficiency can be improved.