Abstract: In order to improve the water-soluble and negative performance of sodium lignosulphonate of coal water slurry dispersant, taking sodium lignosulphonate, sodium methacrylate and allyl polyoxyethylene ether as raw materials, the lignosulfonate graft copolymer (LS-APEG-SMAS) was synthesized by aqueous solution polymerization. The chemical structure of the product was characterized by Fourier Transform infrared spectroscopy (FTIR), and was applied to preparation coal water slurry with Shenhua Coal. The effects of adsorption time and concentration of dispersant on saturated adsorption capacity were investigated. The Zeta potential of the coal after dispersion was measured. The changes of functional groups in the coal before and after dispersion were characterized by FTIR. The surface morphology of coal before and after dispersion was observed by Environmental Scanning Electron Microscopy (ESEM). It is found that when the concentration of dispersant was 600 mg/L, the adsorption capacity reached 8 mg/g at 25 ℃ for 12 h, and the Zeta potential decreased from -8.54 mV to -31.5 mV during the dispersion. The results showed that LS-APEG-SMAS had good dispersion stability.