The invention provides a biomass flue gas dust removing apparatus with self-cleaning function. The biomass flue gas dust removing apparatus comprises a bracket, a shell, a dust filtering device and anash hopper, wherein the dust filtering device comprises a dust removing filtering bag and self-cleaning film layers, the dust removing filtering bag is a hollow cone, the top end of the hollow cone has large diameter, the bottom end of the hollow cone has small diameter, the self-cleaning film layers are arranged on the inner wall and the outer wall of the dust removing filtering bag, the shell is arranged on the bracket, and seals the dust removing filtering device, the ash hopper is arranged below the shell, and the bracket, the shell and the ash hopper are welded into a closed integration.According to the present invention, the cloth bag dust removing device has advantages of good dust removing effect, self-cleaning function, low running cost and long service life, wherein the flue dust is not easily attached to the filtering bag.