The invention relates to a chemical purification method, especially to a copper removal method which is suitable for a nickel electrolysis anolyte purification process. The copper removal method provided by the invention is obviously different from a copper removal method by adding anode mud in nickel ore concentrate as follows: a sodium hydrosulphite solution is added in an iron-removed liquid to activate copper ions and increase reaction probability between copper ions and amorphous nickel sulfide; as amorphous nickel sulfide is added into a copper removal tank in a slurry form, labor intensity is reduced, it is convenient to realize automatic control, and stabilization and continuity of the copper removal process are guaranteed; and as copper slag can directly enter a copper melting system, the technology is optimized, flow of copper impurity in the system is shortened, copper slag is processed not by the use of chlorine, and the environment is improved. Through detection, a copper-removed liquid contains 0.4-2.5ppm of copper. Thus, purification requirements are met. The mass ratio of copper to nickel in the copper slag is 15-17. The copper slag can be directly melted to produce anode plates.