Abstract: The processing technology of sour corn soya-bean milk was studied. Using corn starch conversion product as the lactic acid bacteria fermentation substrate, the orthogonal oxperiments were conducted to determine the main technological factors: the weight ratio of soya to corn liquid is 70∶30, fermentation temperature is 42℃, fermentation time is 6 hours, the weight ratio of L·bulgaricus to S·thermophilus is 1∶2; by adding stabilizer the stratification problem is solved; the lactic acid bactoria is tamed to grow in the soya-bean milk.