The invention relates to a high-roughness electrolytic copper foil, particularly to the high-roughness electrolytic copper foil and a preparation method thereof. The high-roughness electrolytic copperfoil comprises a rough surface and a smooth surface, wherein the smooth surface and the rough surface are bonded with non-woven fabric. The method comprises a first stage: step 1, carrying out brushing treatment on the rough surface of the copper foil through a brushing roller; step 2, carrying out acid pickling on the rough surface; step 3, carrying out roughening copper treatment on the rough surface; step 4, carrying out curing copper treatment on the rough surface; step 5, carrying out galvanizing treatment on the rough surface; step 6, carrying out passivation treatment on the rough surface; and step 7, carrying out drying treatment on the rough surface; and a second stage: step 1, carrying out brushing treatment on the smooth surface of the copper foil through the brushing roller; step 2, carrying out acid pickling on the smooth surface; step 3, carrying out roughening copper treatment on the smooth surface; step 4, carrying out curing copper treatment on the smooth surface; step 5, carrying out galvanizing treatment on the smooth surface; step 6, carrying out passivation treatment on the smooth surface; and step 7, carrying out drying treatment on the smooth surface.