To study the changing trend of wheat quality and microbial community structure during the process from storage to discovery of mycelium. Taking the durum white wheat grains stored in Tianjin City as the research object， and using the triangular flask as the storage container， the wheat was simulated under the conditions of 30 ℃， 60% RH， 40 ℃ and 80% RH， and the storage time was 0-120 days. By monitoring the changes of wheat grain moisture， color difference， protein， fat， starch， fatty acid and other quality indicators， as well as the total number of molds and high-throughput sequencing results， the quality and fungal community structure changes of wheat in the simulated grain depot at different storage stages were evaluated. The results showed that under the conditions of 30 ℃ and 60%RH， the quality of wheat decreased slowly within 120 days of storage， and the relative abundance of Aspergillus increased rapidly from 80 to 120 days. Under the conditions of 40 ℃ and 80% RH， the quality of wheat deteriorated faster. At 60 days， the relative abundance of Aspergillus reached 100%， and the wheat produced visible mycelium. The study showed that with the increase of storage temperature and relative humidity， the change rate of wheat quality was significantly accelerated， and the rate of mycelium production was accelerated.