Abstract: The industrial analysis and instrumental characterization of coal slime from a coal preparation plant in Ningdong were carried out, and the effects of different flocculants, flocculants and their combination on slime sedimentation were studied. The results show that the ash content of the coal slurry is as high as 47.58%, which contains a certain amount of kaolinite and montmorillonite. There are more oxygen-containing functional groups in the slime, and it has certain hydrophilicity, and the Zeta potential is -32.47 mV. There is strong electrostatic repulsion between the solid particles in the slime water, and the slime water system is stable and not easy to settle. Secondly, in slime water sedimentation test, the effect of PAC is better than PAS and PFS, and the best effect is when the dosage of PAC is 15kg/T. The effect of flocculant CPAM is better than Apam, ACPAM and NPAM. The optimum dosage of CPAM is 150g/t. When PAC and CPAM are used together, when the amount of CPAM is 150g/t and the amount of PAC is 10kg/t, the comprehensive index of slime water is the highest. The settling velocity of coal slurry is 0.65 cm·S-1, the turbidity of supernatant is 44.26 NTU, the floc height is 3.57 cm, and the comprehensive index is 1.26 cm·s-1·NTU-1.