The invention discloses a method for obtaining escherichia coli genetic-engineered bacteria of recombinant hybrid cationic antimicrobial peptide CC. The principle of the method disclosed by the invention is as follows: bioinformatics technology and molecular biological technology are combined to select natural antimicrobial peptide with therapeutic potential, a molecular design of the antimicrobial peptide is carried out, the antimicrobial peptide is synthesized to a gene sequence after being translated, and the escherichia coli genetic-engineered bacteria of hybrid cationic antimicrobial peptide CC is constructed by such technical programs as cloning vector construction, expression vector construction, and the like. A DPP tripeptide sequence is arranged between a GST tag and the antimicrobial peptide, and the DPP tripeptide sequence is purified after being expressed. IPTG (Isopropyl beta-D-1-Thiogalactopyranoside) induction is replaced by lactose induction to reduce the cost and optimize the culture conditions and the culture medium composition, and the lactose induction is combined with fermentation. As shown in a biological activity identification result, the escherichia coli genetic-engineered bacteria has a broad application prospect in food, feed and aquaculture due to efficient antimicrobial activity, thermal stability and pH stability and very weak hemolytic activity.