Coal water slurry additive and preparation method thereof

The invention provides a coal water slurry additive. The coal water slurry additive comprises an aniline waste tar modified product sulfamate and polyphenyl glycol siloxane phosphate, the mass ratio of the sulfamate to the polyphenyl glycol siloxane phosphate is 1: (0.2-0.8), preferably 1: (0.3-0.6). And mixing the aniline waste tar modified product sulfamate and polyphenyl glycol siloxane phosphate at 40-60 DEG C for 1-2 hours to prepare the coal water slurry additive. When the prepared coal water slurry additive is used for preparing coal water slurry, the coal water slurry has the characteristics of high concentration, low viscosity, stability and good rheological property, and the slurry concentration can be improved by 0.5-2.5 wt%; meanwhile, the waste tar is used for preparing the coal water slurry additive, the aniline waste tar is comprehensively utilized, the preparation and application cost of the coal water slurry is reduced, the aniline waste tar is used for preparing the additive, energy consumpt