Abstract: In order to study the influence of different treatment methods on the nutritional composition and biological activity of rice buckwheat, germination, fermentation, steaming and fermentation after steaming on the reducing sugar, protein, free amino acids, γ-aminobutyric acid, total phenol, total flavonoids and antioxidant activity. The results showed that after four treatments the content of total polyphenols, total flavonoids, scavenging DPPH free radicals and iron ion reduction ability of rice buckwheat were higher than that of untreated rice buckwheat, while after steamed processing the content of reducing sugar, γ-aminobutyric acid and rutin decreased compared with untreated rice buckwheat. By correlation analysis, the contents of total phenols and total flavonoids were significantly correlated with DPPH free radical scavenging ability and iron ion reducing ability (P<0.01). Among then, the raw rice buckwheat was the best treated by fermentation of lactic acid bacteria, with the highest content of reducing sugar, γ-aminobutyric acid, total phenol, total flavonoids, rutin, respectively, 3.62%, 4.84 mg/g, 13.63 mg/g, 4.63%, 39.80 mg/g and DPPH radical scavenging ability andiron ion reduction ability were the strongest. Therefore, fermentation treatment is a good processing method, which can further improve the nutritional composition and biological activity of rice buckwheat, and can provide a reference for the deep processing and high-value utilization of rice buckwheat.