Blackening electroplating solution and black surface treatment method of rolled copper foil

The invention provides blackening electroplating liquid and a black surface treatment method of rolled copper foil. The blackening electroplating liquid comprises Ni < 2 + >, a complexing agent, a main additive, a first auxiliary additive and a second auxiliary additive, wherein the main additive is any one of Zn, Sn, Mo, W, Al and Cu metal salts; the first auxiliary additive is an organic reducing agent; and the second auxiliary additive is any one or more of Al, Cu, Zn, Sn, Mo, W metal sulfate or metal chloride. According to the blackening electroplating liquid, the novel additive is adopted, the novel additive comprises a plurality of inorganic matters and trace organic matters, the inorganic matters are mainly inorganic salts without Pb, As and Cd, the inorganic matters have the advantages of high sewage treatment efficiency and low treatment cost, and the trace organic matters are easy to decompose and basically have no pollution to the environment. Therefore, compared with an existing sulfur-containing