The localized surface plasmon resonance (LSPR) effect can effectively utilize and transform solar energy, which is an ideal candidate to solve the energy crisis. In particular, plasmon hot carriers generated by LSPR effect are the focus of current research because their energy characteristics are higher than the Fermi level, which can easily promote the chemical reaction on the catalysts and improve the photoelectric performance of the optoelectronic devices. In this review, the generation of hot carriers and their decay pathways under different nano-structured models are discussed, and their unique significance is highlighted. Meanwhile, recent research advances in cognizing the plasmon hot carriers, the role of hot carriers in various applications, and the regulating mechanism of hot carriers in the nanostructure are discussed in depth. In addition, the limitations and challenges of the current research on plasmon hot carriers are presented, and prospects for the future are proposed.