The preparation of composite cementitious materials from tailings is an important way to realize the utilization of tailings industrialization resources and reduce carbon emissions in the construction industry. This paper focuses on the activation mechanism and hydration characteristics of gold ore tailings under different activation methods. High-temperature activation， mechanical activation， and chemical-high temperature-mechanical composite activation were used to enhance gold tailings activity， and the influence of activation methods on gold tailings activity was analyzed. The water consumption and standard consistency setting time were measured to analyze the effect of different gold tailings content on the physical properties of composite cementing materials. The activation mechanism and hydration characteristics of gold tailings were revealed by XRD analysis， SEM analysis， and pozzolans property test. The results show that the activation effect is as follows： chemical-high temperature-mechanical composite activation>high temperature-mechanical composite activation>mechanical activation> thermal activation. Under the chemical-high temperature-mechanical composite activation， the compressive strength ratio of the gold tailings mortar test block in 28 days was 74.98% and 58.25% higher than that of the original gold tailings. The crystallinity of the main mineral phases of gold tailings tends to decrease after high-temperature activation or mechanical activation， but the activity of pozzolanic ash is low. The presence of CaO is helpful for further reducing crystallinity， and the alkaline environment provided in the hydration reaction process can obtain active SiO2 and Al2O3， and accelerate the reaction of Ca（OH）2 with active SiO2 and Al2O3. The content of C—S—H gel and aluminate hydrate increases， the structure is denser， and the compressive strength is improved.