The invention discloses a preparation method of engineering bacteria for efficiently expressing growth hormone. The preparation method comprises the following steps: 1) amplifying human growth hormonehGH gene by a PCR method to obtain an amplified hGH gene; 2) connecting the amplified hGH gene in step 1) to a pMal-p2x vector to obtain recombinant plasmids pMal-hGH; 4) guiding the recombinant plasmids in step 3) into escherichia coli BL21 (DE3), inducing protein expression by IPTG, and after it determines that expression is correct, obtaining the engineering bacteria for efficiently expressingthe growth hormone. The pMal-p2x is taken as vectors separately to obtain recombinant plasmids pMal-p2x-GH, an amino terminal of the recombinant plasmids of pMal-p2x-GH is provided with an MBP protein tag, therefore, the recombinant plasmids are guided into a receptor of the escherichia coli, hGH and MBP tags can be subjected to fusion expression, therefore, hGH is brought to a peripheral mass space, purification of hGH protein is facilitated, moreover, due to the oxidizing environment of peripheral mass, disulfide bonds can be formed correctly by the hGH protein, and thus, the protein has good activity.