To provide a profitable method for purifying a sugar solution, which adopts a technique different from a countercurrent recycling technique, does not cause the problem of impurity leakage before the breakthrough of a resin, and can prevent the proliferation of bacteria.

This method for purifying the sugar solution is characterized by comprising a purifying process for passing the sugar solution as a raw material through a solution-passing tower having a strongly acidic cation exchange resin (C) layer and a weakly basic anion exchange resin (A) layer sequentially formed from the upper side therein from the overhead portion, a C-recycling process for transporting the C layer in the solution-passing tower to a recycling tower, after the solution is passed through the purifying process, supplying an acid-recycling agent from the overhead portion and stopping the supply of the acid-recycling agent, before a resin in the recycling tower is perfectly recycled, an A-recycling process for supplying an alkali-recycling agent to the solution-passing tower having the empty portion in the upper portion from the overhead portion in the form of contacting with the inner wall surface of the empty portion, and a purification-preparing process for supplying the recycled resin (C) to the upper portion of the solution-passing tower to reform the C layer on the A layer, when the resin (A) is recycled, wherein two or more C layers having different recycling rates are formed in the recycling tower, and the C layers are sequentially supplied to the upper portion of the solution-passing tower from the upper layer fraction having a high recycling rate.