In order to fully utilize the by-products of safflower （Carthamus tinctorius） and explore the best ratio of mixing silage in different proportions with forage oats （ Avena sativa ） and safflower stems and leaves， six treatments were designed in this study. Oats and safflower stems and leaves were mixed with fresh weight， and the mixing ratios were 10∶0 （CK）， 9∶1 （H₁₀）， 8∶2 （H₂₀）， 7∶3 （H₃₀）， 6∶4 （H₄₀） and 5∶5 （H₅₀）. Each treatment was repeated in three groups. After sealing and fermentation for 60 days， the samples were taken and analyzed. The fermentation quality， nutritional value and bacterial community structure were determined. The results showed that the sensory evaluation results of the experimental group were still good or above. The pH values of CK group and H₁₀ group were significantly higher than those of other experimental groups （P<0.05 ）. There was no significant difference in ammonia nitrogen content among the experimental groups. The contents of lactic acid and acetic acid in H₃₀ group were significantly higher than those in other experimental groups （P<0.05）， and the contents of acid detergent fiber and neutral detergent fiber were the lowest. There was no significant difference in acid detergent fiber content among the experimental groups. The contents of propionic acid and butyric acid in CK group were significantly higher than those in other experimental groups （P<0.05）. The dry matter content and soluble sugar content increased with the increase of the proportion of mixed silage， while the crude protein content was decreased in the opposite direction. Combined with the comprehensive evaluation of the membership function method， it was concluded that the silage fermentation quality of the H₃₀ group was the best， in terms of microorganisms， at the phylum level， the dominant bacteria in each test group were Firmicutes. At the genus level， except for the unidentified-Chloroplast in the H₄₀ group， the dominant bacteria in the other test groups were Weissella. The results of comprehensive analysis showed that the optimal mixing ratio of oats and safflower stems and leaves was 7∶3， and the fermentation quality and nutritional quality were significantly improved.

Oats  /  Safflower Stems and Leaves  /  Mixed Silage  /  Fermentation Quality  /  Nutritional Components  /  Microorganisms