The invention discloses a dust removal purification device and method for crude coal tar. The dust removal purification device comprises a backwashing filter, a horizontal decanter centrifuge, a residual oil buffer tank, a purified tar tank, a factice tank, a vacuum filter, a dryer and a distillation apparatus, wherein a filter element is arranged in a cavity of the backwashing filter, and dust-containing coal tar is purified continuously through filtering and backwashing of the filter element; residual oil after backwashing enters the horizontal decanter centrifuge for liquid-solid separation, and purified tar and factice are obtained. In order to increase the recovery rate of the purified tar sufficiently, the factice is extracted with a recycling solvent, and final products of a system comprise purified coal tar and dry cinders. The backwashing filter and the horizontal decanter centrifuge are adopted to cooperate with the solvent extraction system for dust removal purification of the crude coal tar, through graded and stepped treatment, the treating capacity of the system is improved sufficiently while the coal tar is recovered to the greatest extent, besides, the solvent is recycled, and energy saving and environmental protection are realized.