In order to improve the texture characteristics of coagulated compound cereal fermented milk, soybean,quinoa, millet and whole milk powder were used as main raw materials. The processing technology of coagulated compound cereal fermented milk was optimized by single factor experiment and Box-Behnken Center design experiment. The results of single factor test showed that when the amount of xanthan gum was 1.25‰, sucrose content was 7.0%, fermentation temperature was 43 ℃, and fermentation time was 10 h, the gel strength of the coagulated compound cereal fermented milk was the largest, which was 2.95 times of that of the control group. Box-Behnken center design optimization results are: xanthan gum addition 1.50‰, sucrose content 7.0%, fermentation temperature 43 ℃, fermentation time 10 h. Under this condition, the hardness value of the coagulated compound cereal fermented milk was 246, and the gel strength value was 22.10. The results provide a theoretical basis for the industrial production of coagulated compound cereal fermented milk.