The invention provides a method for preparing germinated brown rice milk beverage by compound lactobacillus fermentation, which comprises the following steps of: preparing four lactobacillus direct-throwing fermentation agents such as lactobacillus rhamnosus, pediococcus acidilactici, streptococcus thermophilus and lactobacillus brevis; then soaking brown rice for 10 hours at 30 DEG C, and germinating for 12 hours at 2 DEG C to prepare germinated brown rice; adding 3 times water into the germinated brown rice, grinding milk by adopting colloid, gelatinizing and saccharifying the milk, adding 150 grams of direct-throwing fermentation agents into each ton of liquid rice milk, and performing standing fermentation for 6 hours at the temperature of between 38 and 40 DEG C; and centrifuging the liquid rice milk at 5,000 revolutions per minute, removing residue, adding xylitol according to the clear liquid volume for blending, filtering the liquid by using a hollow fiber membrane, performing ultrahigh-temperature instantaneous sterilization for 2 seconds at 143 DEG C, and filling the liquid with pillow-type package or tetra package to obtain a finished product.