Etching solution for producing differentiated etching between copper layer and electroplated copper layer and preparation method of etching solution

The invention discloses an etching solution capable of enabling a copper layer and an electroplated copper layer to generate differential etching and a preparation method thereof. The preparation method comprises the following steps: S1, a raw material preparation stage; s2, a classification mixing stage; s3, a crude product filtering stage; s4, a sampling and quality inspection stage; and S5, a finished product sub-packaging stage. According to the etching liquid capable of enabling the copper layer and the electro-coppering layer to generate differential etching and the preparation method of the etching liquid, when a chemical copper layer and the electro-coppering layer which are made of the same material are etched, the chemical copper layer is etched by shielding and covering the electro-coppering layer and spraying an etching mixture mixed with a small amount of auxiliaries in a classified spraying and etching mode; after etching is completed, the chemical copper layer is covered, then an auxiliary agen