With the decline in ore grade and the adjustment of production processes within the steel industry, the composition and structure of slag changes, resulting in the decrease of cementitious activity of slag and rendering its utilization in cement-based materials. Based on the composition and structure of slag, this paper analyzes the potential factors influencing the hydration activity of slag. It reviews traditional slag activation methods and their corresponding issues, elucidates the mechanism of action, advantages, and disadvantages of alkanolamine complexation activation method, and introduces a novel slag activation approach based on the synergistic effect of complexation and carbonation, which aims to enhance the resource utilization rate of slag.