Safety issue of lithium-ion batteries (LIBs) such as fires and explosions is a significant challenge for their large scale applications. Considering the continuously increased battery energy density and wider large-scale battery pack applications, the possibility of LIBs fire significantly increases. Because of the fast burning and the easy re-ignition characteristics of LIBs, achieving an efficient and prompt LIBs fire suppression is critical for minimizing the fire hazards. Different from conventional fire hazards, the LIBs fire shows complicated and comprehensive characteristics, and an effective and suitable fire-extinguishing agent particularly designed for LIBs is highly desirable. Considerable efforts have been devoted to this topic, to the best of our knowledge, a comprehensive review on this regard is still rare. Moreover, in practice, a guidance for the design and selections of a proper fire-extinguishing agent for LIBs is urgently needed. Herein, the special mechanisms and characteristics for LIBs fire and the corresponding design principles for LIBs fire-extinguishing agent were introduced. It is revealed that a fire-extinguishing agent developed for LIBs fire will most likely need a high heat capacity, high wetting, low viscosity and low electrical conductivity. After a comprehensive comparison of these agents in terms of these performances, water-based fire-extinguishing agents show best. Several typical fire-extinguishing agents such as gaseous agents, dry powders, water-based and aerosol fire-extinguishing agents were then introduced, and their fire extinguishment mechanisms were presented. Finally, their effectiveness in suppressing the fire were summarized. Water-based fire-extinguishing agents possess high cooling capacity and excellent anti-reflash performance for the fire. We believe this review could shed light on developing an efficient fire-extinguishing agent particularly designed for LIBs.