With the rise and development of high-throughput sequencing technology, omics technology, bioinformatics technology, some achievements have been made in the study of the relationship between the two strains in vitamin C (Vc) microbial fermentation. Therefore, this paper reviews the current research on the companion mechanism between the two strains based on spores, amino acids, B-group vitamins, environmental stress and small molecular substances, and provides some new ideas for the further research.