Abstract: This is an article in the field of mining engineering. Kaolinite and montmorillonite are the main clay minerals in coal slime, and clay minerals are the main factors affecting the sedimentation of coal slime. This paper takes clean coal, kaolinite and montmorillonite as the research objects. The influence of ultrasonic intensity, action time, and ultrasonic pulse interval on its sedimentation effect and floc diameter was investigated. The test results show that when the ultrasonic density is 0.4 W/cm³, when the ultrasonic action time is 2 min, the sedimentation speed of kaolinite and montmorillonite are improved. Further choosing the appropriate ultrasonic pulse interval can further improve the sedimentation effect, but ultrasonic treatment is not conducive to the clean coal settlement. Further, the clean coal, kaolinite and montmorillonite samples were mixed at a ratio of 2:1:1, and the ultrasonic pulse interval time was changed to perform ultrasonic treatment. The results showed that: for the mixed sample, it settled without ultrasonic treatment, the velocity is 2.67 cm/min. When the ultrasonic density is 0.2 W/cm³ and the ultrasonic pulse interval is 4 s, the settling velocity is increased to 5.41 cm/min. Image analysis and potential characterization show that the proper ultrasonic pulse interval time enables the drug to play more fully, and then the electric double layer is compressed to the greatest extent, and finally the particle agglomeration and the growth of flocs are the best.