Particle emissions released by lithium-ion traction batteries (LIBs) during thermal runaway (TR) are considered to be one of the fire hazard sources for new energy vehicles. Moreover, the particle emissions may persist in the environment and cause damage even after a fire is extinguished. Therefore, the formation mechanisms of the particle emissions from LIBs during TR are summarized firstly in this review. Effects of influencing factors on particle emission characteristics and biotoxicity are also explored. Furthermore, simulation models of LIB particle emissions are summarized. Particle emissions calculated for 2021 to 2023 are presented, and particle emissions from 2024 to 2030 are predicted. Finally, the existing research results and the problems with LIB particle emissions are summarized, and future research challenges and directions are prospected. This review aims to evoke interest in particle emissions from lithium-ion traction batteries during TR and provide a reference for suppressing and managing particle emissions to improve the safety of LIBs and mitigate environmental hazards.