Cooked wheat qu is a kind of wheat qu that pure culture of Aspergillus flavus， which is widely used in modern Huangjiu production. To explore the mechanism of cooked wheat qu in Huangjiu fermentation， the influence of cooked wheat qu on Huangjiu brewing was analyzed by controlling the proportion of it. Further， the autolysis characteristics of Aspergillus flavus mycelia (autolysis) was studied， and the influence of mycelia autolysis on Huangjiu was analyzed by co-culture experiment of Aspergillus flavus mycelia (autolysis) and spores (not autolysis) with yeast. The results showed that， with the increase of the proportion of cooked wheat qu added， the S. cerevisiae biomass in the fermentation system significantly increased by 37.61% to 135.90%， and the alcohol content， ammonia nitrogen， amino acid and organic acid significantly increased by 15.87%， 70.00%， 28.46% and 92.41% respectively. Furthermore， the study on the autolysis of Aspergillus flavus mycelium found that the autolysis of mycelium can provide amino acids， sugars， nucleotides and other biomolecules substances for the fermentation system， effectively increase the S. cerevisiae biomass in the fermentation system by 1.32 times， and significantly affect the content of ethanol， ammonia nitrogen， fusel and amino acids. Above all， on the one hand， cooked wheat qu can promoting Huangjiu fermentation by making use of its rich enzyme substances to promote the decomposition of raw materials； on the other hand， a large number of mycelium in cooked wheat qu has autolysis in the fermentation process， which provide nitrogen sources for the fermentation mash and affects the general parameters and flavor compound formation.