Abstract: The scanning electron microscope, laser particle size analyzer, specific resistance test instrument and X-ray diffractometer were applied to the qualitativ e and quantitative analysis on the fly ash particle form, particle size, specific resistance, ash composition and other electrostatic dust collection features .An electrostatic dust collection experiment was conducted with the self made dust collection device. The results showed that the fly ash particle form after the coal water slurry combust ed was various, including the unburned carbon, floating beads and micro beads.The particle size distribution was uneven and the percentage of the coarse particle was high.The major composition of the fly ash was SiO2 and AI2O3, which were taken 70%-90% of the total quantity.Under the same temperature, the specific resistivity of t he fly ash from the coal water slurry would be one to two magnitude orders higher than the fly ash of fine coal.The dust collection rate of the fly ash from the coal water slurry would be higher than the fly ash of fine coal and was 98%.The fly ash of the coal water slurry would be more favorable than the fine coal to the electrostatic dust collection.