Quartz sand purity dictates its applications, with current research focusing on flotation purification. To investigate the effects of ultrasonic pretreatment on quartz flotation, an RKIII single-tank flotation machine was employed at a neutral pH of 6.8, and the impacts of varying ultrasonic powers (120-300 W) and different treatment durations (0-25 min) were discussed. Additionally, ultrasonic pretreatments were carried out in acidic and alkaline environments simulated by 1%-5% solutions of hydrochloric acid and sodium hydroxide, respectively. Through the analysis of impurity content in quartz sand, it was found that under natural pH conditions and a power range of 120-300 W, the optimal purification effect was achieved by adding 100 g of quartz sand to 1200 cm³ of deionized water and subjecting it to ultrasonic treatment for 10-15 min. As the ultrasonic power increased, the purification effect was enhanced. The results showed that the removal of Fe₂O₃, TiO₂, and Al₂O₃ was increased by 10.4%, 3.3%, and 1.2%, respectively, compared with that of the conventional flotation after ultrasonic pretreatment for 15 min with ultrasound power 240 W in a neutral environment. In the optimal 5% HCl solution, the removal rate of Fe₂O₃ was 11.2% and 21.6% higher than that of the control group and the untreated group, respectively. The removal rate of TiO₂ was 4.6% and 7.9% higher, respectively. The removal rate of Fe₂O₃ increased by 23.2% and that of TiO₂ increased by 9.1% with 240 W ultrasonic treatment in 4% NaOH solution.