Energy-saving and environment-friendly surface treatment process for metal surface

The invention discloses an energy-saving and environment-friendly surface treatment process for a metal surface. The energy-saving and environment-friendly surface treatment process comprises the following steps: S1, primary surface treatment; s2, primary cleaning; s3, carrying out secondary surface treatment; s4, cleaning for the second time; s5, drying; s6, wastewater pretreatment: carrying out adsorption treatment on the wastewater in a wastewater pretreatment box through activated carbon to remove heavy metal ions; s7, secondary treatment of the wastewater: introducing the pretreated wastewater into a wastewater purification device, carrying out photocatalytic treatment on the wastewater in the wastewater purification device, filtering the wastewater subjected to photocatalytic treatment through a reverse osmosis membrane, and introducing the wastewater into a water storage tank; and S8, waste water recycling, wherein the water storage tank communicates with the first cleaning pool and the second cleaning