Li‐ion batteries are essential technologies for electronic products in our daily life. However, serious fire safety concerns that are closely associated with the flammable liquid electrolyte remains a key challenge. Tremendous effort has been devoted to designing non‐flammable liquid electrolytes. It's critical to gain comprehensive insights into non‐flammability design and inspire more efficient approaches for building safer Li‐ion batteries. This review presents current mechanistic understanding of safety issues and discusses state‐of‐the‐art non‐flammable liquid electrolytes design for Li‐ion batteries based on molecule, solvation, and battery compatibility level. Various safety test methods are discussed for reliable safety risk evaluation. Finally, the challenges and perspectives of the non‐flammability design for Li‐ion electrolyte are summarized.This article is protected by copyright. All rights reserved