Rum fermentation is driven by microbial consortia dominated by yeast. The interactions among yeasts in the fermentation system are the key to the formation of rum flavor. Investigating the interactions between Saccharomyces cerevisiae and non-Saccharomyces yeast species will contribute to understanding the relationship between yeast and rum quality, which is of great significance for fermentation process control, production efficiency improvement and rum quality enhancement. In this article, the microbial community diversity and the interactions among yeasts during rum fermentation are reviewed. Furthermore, the beneficial effects of co-fermentation with S. cerevisiae and non-Saccharomyces yeasts on the flavor quality of rum are also summarized. Finally, the limitations of current research are discussed in order to provide a theoretical basis for improving the flavor quality of rum.