Mao-tofu is famous for its unique flavour and texture in Anhui Province, China. The physicochemical properties and microbial diversity of Mao-tofu during different fermentation periods were studied. The pH of the tofu was acidic, the moisture gradually decreased, and the hardness, viscosity, and chewiness gradually increased, while the elasticity gradually decreased. Among these, changes in volatiles and synergistic effects of proteins, peptides, and free amino acids (FAAs) affect the flavour of Mao-tofu. Histamine had the highest concentration among all biogenic amine (BA) during the whole fermentation process. A microbial community analysis showed that