<p>Cephalopods are marine molluscs widely distributed in various marine ecosystems. As the “radula” of cephalopods, the beak has broad functions and the phylogenetic and ecological features of beak shapes have been confirmed. However, the ecological pressures on the morphological features of the beak of most cephalopods remain unknown and the relationship between beak morphology and its function has not been explored. In the study, lateral profile images of 1344 upper beaks and 1395 lower beaks of 45 cephalopods were obtained to evaluate the phylogenetic, ecological, and functional signals of beak morphology with the established phylogenetic framework based on genes and reveal the possible ecological and functional significance of beak shapes. The shapes of the upper and lower beaks showed a moderate but slightly low phylogenetic signal, with beak morphology effectively predicted by trophic niche, habitat environment, and distribution range. Cephalopods with different beak functions across various habitats exhibited significant differences in beak shape. The study demonstrated that the evolution of ecological and functional types in beaks could be ascribed to their morphological adaptation to feeding, habitat, distribution, and functional categories.</p>