<p>In order to reduce the environmental harm caused by the production of traditional cement, the feasibility of preparation for clinker-free cement based on lithium slag and quicklime was investigated in this paper. Meanwhile, the effect of Na₂SO₄ on the reactivity of lithium slag was studied. The hydration degree, hydration products and microstructure of clinker-free cement paste were analyzed by FTIR, XRD, TG-DTG, NMR, and SEM, respectively. The results indicate that lithium slag itself does not have the ability to hydrate. However, the clinker-free cement paste prepared with lithium slag can harden after adding quicklime, due to the formation of hydration products C–(A)–S–H gel and AFt. Adding Na₂SO₄ can enhance the reactivity of lithium slag, and further increase the amount of hydration products. Moreover, the compressive strength of clinker-free cement paste with lithium slag and quicklime is improved (25.6&#xa0;MPa at 28 d). This paper not only verifies that lithium slag and quicklime can be used to prepare the clinker-free cement, but also provides a theoretical basis for the addition of Na₂SO₄ to enhance the reactivity of lithium slag.</p>