The invention discloses a production method of low-
sugar soya-bean milk, which mainly comprises the following steps: (1) pretreatment: soybean extracting solution is filtered by a filtering bag, suspended matters such as bean dregs in the soybean extracting solution can be removed, so as to ensure the safety of a membrane
system and obtain clear solution of the soybean extracting solution; (2)
sugar removal by hyperfiltration: the clear solution of the soybean extracting solution, which is pretreated, enters into a hyperfiltration membrane
system, hyperfiltration concentration is carried out,and the solution is concentrated by two times, water is added in the concentrated solution for washing, so as to wash
sugar ingredient in the concentrated solution in a circulating way and measure thesugar degree in the concentrated solution and dialysate at regular time, until the sugar ingredient in the concentrated solution is reduced to be stable, the treatment of sugar removal by hyperfiltration is stopped; (3)
nanofiltration and contraction: the hyperfiltration dialysate is placed in a
nanofiltration membrane
system, the sugar ingredient in the dialysate is concentrated and extracted, and the
nanofiltration dialysate water returns back to the production to be used as pulping water. In the whole treating process, other substances are not added, the treatment is carried out at normaltemperature, and the method has the advantages of energy saving,
environmental protection and good separating effect.