A method for inducing continuous separation of copper ions from copper using UV-light source, comprising the following steps: (1) cutting apiece of copper into wires or slices for immersing into a vessel containing water; switching on a stirrer for stirring the water continuously and keeping the copper being immersed in the water; (2) turning on the UV-light source for irradiating the copper and the water continuously; appearing a large amount of white precipitate in the water; (3) filtering the solution; detecting the filtered solution, a certain concentration copper ions in the filtered solution are found; adding hydrochloric acid by drops into the unfiltered original solution, the white precipitate is dissolved and copper ions are detected. The invention makes the copper separate out copper ions continuously and can be applied to copper ion disinfection for swimming-pool water, scenic water and cooling water, etc.