Abstract: In order to improve the activity of copper tailings and prepare the gel material of whole tailings, the mechanical ball mill, anhydrous Na₂CO₃, Na₂SO₄ and copper tailings improved the reactivity of copper tailings.By adjusting the amount of sodium salt and milling time, the particle size distribution and mineral phase change during mechanochemical milling are analyzed.The 28 days compressive strength of the ball milling activated copper tailings cementitious material is used to characterize the activation effect.The hydration reaction mechanism of copper tailings is clarified by XRD, TG-DTG, FT-IR, SEM-EDS and other characterization methods.The research results show that the activation effect of copper tailings is the best when the content of Na₂CO₃ and Na₂SO₄ is 50% and 25% respectively, and the milling time is 40 min and 60 min respectively.After sodium salt ball milling, the particle size of copper tailings is reduced, the particles are homogenized, and the main crystalline minerals such as quartz, muscovite, phyllite, calcium silicon oxide are amorphous.The 28 days compressive strength of sodium salt ball milling activated copper tail-based cementitious material (CCT and SCT) reaches 55.4 MPa and 30.7 MPa, respectively.Compared with mechanical ball milling copper tailings (CT), the compressive strength is increased by 13 times and 7 times respectively.The addition of sodium salt has no effect on the type of copper tailings hydration reaction products.The active copper tailings mainly generate C—S—H gel, N—A—S—H gel, short rod ettringite and other hydration products through hydration reaction, so that the active copper tailings based cementitious material show good mechanical properties.