The present study investigated the 75 molds isolated from Daqu of Shanxi aged vinegar using morphological and ITS sequencing approach. The results showed that Aspergillus niger and Rhizopus oryzae are the dominant bacteria in Daqu， they accounted for 13% and 28% respectively. One excellent strain of Aspergillus niger 186 was screened， with higher glucoamylase of 4 279.11 U/g and cellulase of 476.60 U/g producing ability. The interaction with Aspergillus niger 186 and Rhizopus oryzae 774-2 was investigated. The results showed that when the ratio of Aspergillus niger 186 and Rhizopus oryzae 774-2 was 1∶5， the production of protease and organic acid was significantly higher than that of pure culture of Aspergillus niger 186. Additionally， the ester yield of the co-culture system was also increased by 6.07%. Simultaneously， the variety and content of volatile aroma components were largely enriched. In summary， the characteristics of enzyme and flavor production of different mixed-culture fermentation system were significantly different. It was of great significance to find the optimal combination and proportion of mixed strains to improve the production efficiency and product quality of Shanxi aged vinegar.