The invention discloses a method for treating glass cutting wastewater. The method comprises the following steps: (1) introducing an alum solution with a mass fraction of 5-15% into a flocculation reaction tank, stirring while introducing, introducing the glass cutting wastewater into the flocculation reaction tank, and continuously stirring for 15-20 minutes to obtain a mixed solution, wherein avolume ratio of the glass cutting wastewater to the alum solution is (200-500):1; and (2) introducing the mixed solution into a lamella setting basin for standing for 1-1.5 hours, and recovering the supernatant, wherein the inclination angle of the lamellas in the lamella setting basin is 60 degrees, and the horizontal spacing between the lamellas is 10cm. According to the method, the content of suspended solids in the glass cutting wastewater can be reduced, and the treatment effect is excellent. Since only the alum serves as the flocculating agent for performing the conventional stirring andsettling operations in the process, the steps are simple and feasible, and the cost is low.