Abstract: The aims of this study was to seek optimal mixed silage treatment of Astragalus adsurgens and corn, improve the fermentation and nutritional quality of Astragalus adsurgens, and reduce the content of poisonous substances. Special silage corn of Keduo 8 and Astragalus adsurgens were mixed and silaged at the ratio of 1:0, 2:1, 1:1, 1:2 and 0:1, respectively, and 3 repetitions per treatment. The pH value, volatile fatty acids, nutrition composition, mycotoxin, nitrate and nitrite, inorganic toxic elements in all treatments determined. The result showed that with the proportion of Astragalus adsurgens increasing, pH and the crude protein content would increase as well, while the neutral detergent fibre and acid detergent fiber had a descending trend. The content of lactic acid of corn mixed with Astragalus adsurgens 1:1 treatment was highest. The mixed silage could raise the amino acid content of the silage. The Methionine content of three mixed silage treatments was 0.029 4, 0.035 1 and 0.025 4 μg·kg-1 respectively, which was all higher than that of single Astragalus adsurgens silage (P＜0.05), the Lysine was 57.2% and 45.0% higher than that of single corn silage (P＜0.05). The aflatoxin of treated silages were higher than those of raw silage, while the zearalenone, nitrite, nitrate were lower. The influence of silage on inorganic elements like lead, arsenic, chromium was not significant. These results indicate that nutrient and amino acid content of the mixed silage of corn mixed with Astragalus adsurgens 1:1 treatment are relatively high and less poisonous elements are contained, which is the ideal mixed silage treatment.