Copper electroplating liquid

The invention provides a copper electroplating liquid. The copper electroplating liquid is composed of the following components: 70-90g/L of copper pyrophosphate (Cu2O7P2), 300-350g/L of potassium pyrophosphate (K4O7P2), 2-5ml/L of ammonia water (NH3.H2O) and the balance of deionized water. The pH value of the copper electroplating liquid is within the range of 8.5-9.2. The copper pyrophosphate is used for providing copper ions for the electroplating liquid and increasing the conductive action; the potassium pyrophosphate mainly plays a role in electric conduction, thereby improving the dispersity of the copper pyrophosphate in the electroplating liquid and maintaining the stability of the electroplating liquid; the ammonia water is used for improving the brightness of a coating. As the copper electroplating liquid is free from cyanides, the wastewater is easy to treat, the production cost is low, and the environmental pollution is avoided.