The work aims to investigate the effect of different compositions of co-blended film on the post-harvest quality and microflora structure of Allium Mongolicum Regel (A.mongolicum). The PBAT/PP blend films was prepared by melt extrusion, then barrier properties and the effects on postharvest quality and microbiological population of A.mongolicum of PBAT/PP blend films were studied. The results showed that PBAT/PP blend system was incompatible. With the increase of PBAT content, the transmission properties of CO2 and H2O were enhanced. When the addition of PBAT was increased to 30%, the CO2 transmission coefficient, CDP/OP and H2O transmission coefficient were increased by 49.7%, 50.7% and 145.5%. PP/PBAT(30%) film of 35 μm thickness could formed gas environment that matched the physiological characteristics of A.mongolicum, with O2 ranging from 0.48% to 0.66% and CO2 ranging from 5.98% to 6.53%. It also could significantly reduce respiration rate, under low O2 and high CO2 environment, Aerobic bacterial count (ABC), Psychrophile plate count (PPC), Pseudomonas count (PC) are effectively inhibited on the surface of A.mongolicum. Compared with PP packaging, ABC decreased by 1.1 lg CFU/g, PPC decreased by 1.3 lg CFU/g, PC decreased by 1.47 lg CFU/g. It was concluded that A.mongolicum packed in PP/PBAT(30%) film with a thickness of 35 μm was effective in reducing respiration rate and microbial proliferation infestation and maintaining stable postharvest quality.