To explore the effects of moisture content and mixing ratio on the silage quality of Avena sativa and Sesbania cannabina mixed silage， this experiment was designed with three moisture content gradients （55%-60%， 60%-65%， 65%-70%） and seven mixing ratios （fresh weight ratio from 100∶0 to 0∶100）. Samples were vacuum ensiled for 60 days， after which nutritional and fermentation quality indices were determined， and a comprehensive evaluation was conducted using the membership function method. The results showed that moisture content， mixing ratio， and their interaction had significant effects on silage quality （P<0.05）. With the increase of moisture content， dry matter （DM）， crude protein （CP） and water-soluble carbohydrates （WSC） decreased， while fiber content， lactic acid （LA） content and relative forage quality （RFQ） increased. pH and butyric acid （BA） decreased first and then increased， and acetic acid （AA） increased first and then decreased. Among the mixing ratios， Avena sativa silage had the highest DM content， Sesbania cannabina silage had the highest CP， WSC， and LA contents， and the 30∶70 mixture （Avena sativa∶Sesbania cannabina） exhibited the optimal RFQ. Higher Sesbania cannabina ratios resulted in lower fiber contents. The pH values of all treatments were below 4.2. Comprehensive evaluation revealed that the mixed silage with 60%-65% moisture content and an Avena sativa-to-Sesbania cannabina ratio of 30：70 performed the best， and Sesbania cannabina silage with 55%-60% moisture content also showed excellent quality. The former can be recommended in production to achieve balanced nutrition， and the latter can be adopted for high nutrient value and single raw material utilization.

Moisture content  /  Mixing ratio  /  Avena sativa  /  Sesbania cannabina  /  Silage quality