Pyrroloquinoline quinone (PQQ) is a peptide-modified natural product, which is the third type of coenzyme after nicotinamide and riboflavin, and has important physiological functions such as anti-oxidation, anti-aging and immunity enhancement, and is of great value in the fields of medicine and health care. At present, there are still many problems in the large-scale preparation of PQQ, which limit the wide application of PQQ. There is an urgent need for a low-cost synthesis method to realise its broad application potential. The recent research developments and trends in the analysis of PQQ biosynthesis pathway, catalytic reaction mechanism of key enzymes and the selection and breeding of high-yielding strains are reviewed, and suggestions and prospects for the research strategy of PQQ biosynthesis microbial cell factory construction are provided.