Abstract: In order to explore the interaction between particles in coal slime water under electrochemical action and its influence on condensation and settlement effect, first, under the condition of different potential gradient sedimentation experiment was carried out on the original coal slime and suspension, and then by coal, illite, coal and illite system as the research object, through the determination and calculation different electrochemical conditions of the coal and illite Debye length, zeta potential and surface energy parameters, with the aid of EDLVO theory for calculation, interaction energy between particles and scanning electron microscope before and after electrochemical treatment on coal and illite surface microstructure observation, the study and analysis of electrochemical mechanism. The settlement test results showed that the electrochemical action worsened the settlement effect of coal suspension and improved the settlement effect of clay suspension. The settlement effect was the best when the potential gradient was 2 V/cm for the original coal slime, coal and clay suspension, and the curve variation trend was basically the same. The results of EDLVO showed that under electrochemical action, the total interaction energy between coal particles increases, and the attraction energy decreases. The total interaction energy between illite, coal and illite particles decreased, and the repulsion energy decreased. And the three suspension systems are polar attraction can play a dominant role. The electrochemical action can obviously reduce the "energy barrier" of the total interaction energy between particles. When the potential gradient is 2 V/cm, the total interaction between coal and illite particles can reach the minimum value. The theoretical calculation results are consistent with the settlement test results, and the action mechanism of electrochemical action to promote the coalesce and settlement of lignite slime water is analyzed.