Abstract: In this paper, the effect of ultrasonic treatment on the floatability of suppressed calcite in sodium silicate and sodium oleate system was studied and the mechanism of ultrasonic treatment was explored. The test results show that the flotation recovery of calcite can be greatly increased from 7.5% to 82.1% under the conditions of ultrasonic cleaning machine power of 150 W, frequency of 40 kHz and ultrasonic treatment time of 20 min. Ultrasonic treatment can reduce the pH value of pulp and increase the overall temperature of pulp, but the range of change does not affect the floatability of calcite. Increasing the temperature of water medium in ultrasonic cleaning machine has a synergistic effect on improving the floatability of calcite. Under the conditions of 150 W power, 40 kHz frequency, 10 min ultrasonic time and 70 ℃ water medium temperature, the flotation recovery of calcite can reach 86.2%. Ultrasound can selectively weaken the inhibitory effect of sodium silicate on calcite, but does not affect the collection effect of sodium oleate on calcite. Ultrasonic treatment can promote the dissolution of sodium silicate adsorbed on calcite surface, but has little effect on sodium oleate adsorbed on calcite surface.