Abstract: This paper conducted the research on the lignite dewatering effect played by the different coal slurry concentration,electrolysis time,electrolysis current,the type and amount of electrolyte with the method of electrolysis and filtration.It was shown that electrolysis and filtration were beneficial for the lignite dewatering,especially for the removal of water inside.It was concluded that the cake could be with the lowest moisture and the rate of filtration was increased with the condition: the coal slurry concentration was 150g/L,the electrolysis time was 30min,the electrolytic current was 0.75A,the electrolyte was Al₂（SO₄）₃,and the amount of electrolyte was 1 000g/t.