Abstract: Nano-boron nitride (nano-BN) is a kind of nanomaterials with exceptional mechanical properties, thermal stability and electrical conductivity, and has broad application prospects in industry, energy, electronics and biomedicine. However, with the continuous expansion of its applications, the health effects and potential toxicity of nano-BN on organisms have gradually emerged, and become one of the current research hotspots of nano-BN. The toxicity studies of nano-BN will not only contribute to understanding its potential hazards but also provide crucial theoretical foundations for its safety assessment and health risk evaluation. Therefore, it is of great significance to comprehensively analyze and review the available in vivo and in vitro toxicity studies of nano-BN. This paper discussed the reported influencing factors of nano-BN toxicity, including its morphological characteristics, surface modifications, cell types, exposure dose and time, and further analyzed the oxidative stress, mitochondrial damage, DNA damage, and other related toxic mechanisms induced by nano-BN. Currently, the toxicity research of nano-BN remains limited, particularly due to insufficient human exposure data, unclear chronic toxicity in vivo, and restricted use of cell types for in vitro experiments. Future research should focus on these gaps.