An evaporation heat transfer tube has a tube main body and a step-like structure; outer fins are arranged at intervals on the outer surface of the tube main body and an inter-fin groove is formed between two adjacent outer fins; the step-like structure respectively abuts against the bottom plane and one of the side walls of the inter-fin groove. The step-like structure has a first surface, a second surface and at least one flange formed by the intersection of the two surfaces, wherein the first and the second surface intersect respectively with the side wall and the bottom plane.