A pre-treatment solution for coating a copper layer on a magnesium alloy, the pre-treatment solution comprising an aqua solution added with copper ions, a complexing agent and an additive, wherein
- the complexing agent is selected from the group consisting of potassium sodium tartrate, potassium tartrate, sodium tartrate, tartaric acid, and dissolvable salts derivative from tartaric acid;
- and
- the additive is selected from the group consisting of sodium phosphate, sodium hypophosphite, phosphoric acid and dissolvable salts derivative from phosphoric acid or hypophosphite acid.