The invention discloses metal surface micro-etching liquid and belongs to the technical field of chemical engineering micro-etching liquid. The metal surface micro-etching liquid is prepared from, by mass, 15-25% of dilute sulphuric acid with the mass fraction being 50%, 10-15% of hydrogen peroxide, 2-5% of a stabilizing agent, 0.5-1% of surfactant, 0.2% of an anti-mildew agent and the balance water. The metal surface micro-etching liquid has a quite remarkable effect on solder resist preprocessing and surface chemical treatment of a printed circuit board, the copper face of the circuit board has uniform roughness and cleanness, the binding force between the copper face and an image layer and a pasted film is increased, toxicity is low, pollution is small, use is convenient, metal surface oxide can be fast processed, and metal surface cleanness is improved. The micro-etching liquid product is wide in application range and mainly used for metal surface oxide removing preprocessing and metal coloring preprocessing. The metal surface micro-etching liquid can also be used for super roughening, oxide removing processing, machining, metal deep machining, spraying and other the metallurgical industries of electronic circuit board copper faces.