<p>Developing and utilizing high-extreme pressure (EP) performance solid lubricants has become imperative to meet the lubrication requirements for harsh operating conditions. Based on the action mechanism of rare earth on alloys, the influence of material corrugated layered crystal structure, and sulfur content on lubrication properties at the atomic and molecular levels, layered rare earth sulfates have become a new type of high EP performance solid lubricants. Herein, we prepared layered rare earth sulfate materials (RE₂(OH)₄SO₄·nH₂O, RE = La/Sm/Ce, i.e., RES, LaS, SmS, CeS, respectively) using a mild hydrothermal method for controlled particle size and morphology. To evaluate its applicability, we tested the new solid lubricants against high load, high temperature, long-term, different friction pair materials, and fretting. Overall, the RES samples exhibited excellent lubricating behavior when added to polyurea grease, better than MoS₂. By adding layered lanthanum sulfate, samarium sulfate, and cerium sulfate, the seizure loads can reach up to 1400, 1300, and 1300 N, respectively. Microscopic analysis of the friction pairs confirmed that the lubricating films formed on the worn surface during friction. Excitingly, the RES materials exhibited excellent synergistic effects on EP performance and corrosion resistance. Thus, these materials have broad application prospects as lubricants.</p> Graphical Abstract <p></p>