The invention relates to a method for promoting bacterial growth by utilizing low-temperature protease, and belongs to the technical field of molecular biology and biology. The method comprises the steps that the low-temperature protease is added into a prepared LB culture medium, the addition amount of the low-temperature protease is 1-5% (g/L) of the volume of the culture medium, after the reaction is conducted for half an hour at the indoor temperature, high-temperature sterilization is conducted, and bacterial inoculation and culturing are conducted according to the conventional operation.The method can promote bacterial growth, shorten the growth period, and solve the problem that in the primary culturing period, bacteria grow slowly.