Chain couplings are a widely used type of flexible mechanical coupling, primarily used to connect two shafts for torque transmission, while compensating for axial, radial, and angular misalignment to a certain extent. With advantages including high torque density, simple structure, easy installation and maintenance, and cost-effectiveness, chain couplings are extensively applied in machinery, metallurgy, mining, chemical, and transportation industries. This article systematically reviews the structural composition, working principles, performance characteristics, selection criteria, installation and maintenance guidelines, and typical industrial applications of chain couplings.