E.coli is one of the most widely used expression hosts for the production of recombinant proteins. It is often the first system chosen for producing target proteins due to its advantages over other systems, such as rapid proliferation, high expression, easy purification, good stability and low cost. Although there are some difficulties in the E.coli expression system, such as codon usage bias in the target gene sequence or imbalance between protein aggregation and solubilization, which may lead to the failure of target protein expression/low expression or result in the formation of protein aggregates (commonly known as inclusion bodies).