Abstract: In order to improve the nutritional and functional value of the mixed congee products, and to improve its stability, the experiment was carried out to prepare mixed congee powders through pulverisation treatments including general (3000 r/min, 1600 W) and superfine grinding (−20 ℃, 960 r/min, 1100 W). The effects of superfine grinding on the particle size distribution, color parameters, hydration properties, filling properties, fluidity properties, micro structure, antioxidant activity, the dissolutions of flavonoids and total polyphenols were investigated, which would provide reference for the application and promotion of superfine grinding in mixed congee processing industry. The results showed that superfine grinding had a significant effect on the physicochemical and functional properties of mixed congee powder (P<0.05). After superfine grinding, the specific surface area of mixed congee powder was significantly increased, the water holding capacity and swelling capacity were reduced, and the stability and fluidity was significantly improved. Compared with coarse ground mixed congee powder, the reducing power and DPPH radical scavenging capacity of superfine powder through 300 mesh sieves were increased to 0.80 and 59.98% respectively, and the dissolution of total phenols and flavonoids increased to 2.14 and 11.33 mg/g, significantly higher than general grinding samples (P<0.05). In conclusion, the superfine grinding treatment improved the physicochemical and functional value of the mixed congee products, and could provide a certain theoretical basis for in-depth research and processing of mixed congee powder.