The invention aims to provide a bionic passive flexible low-energy-consumption ankle and foot prosthesis based on rigid-flexible coupling. The bionic passive flexible low-energy-consumption ankle andfoot prosthesis based on the rigid-flexible coupling comprises a shank part, and a foot part; the shank part comprises an upper shell, an upper shell connecting plate piece, an auxiliary metatarsal dorsiflexion limit assembly, a middle shell, a passive support and upper-middle shell connecting piece, a lower shell, an introversion and extroversion limit assembly, and a passive support and middle-lower shell connecting piece; the upper shell, the upper shell connecting plate piece, the auxiliary metatarsal dorsiflexion limit assembly, the middle shell and the lower shell are all made of hard materials; and the passive support and upper-middle shell connecting piece and the passive support and middle-lower shell connecting piece are both made of soft materials. The bionic passive flexible low-energy-consumption ankle and foot prosthesis based on the rigid-flexible coupling has the characteristics of being high in flexibility, self-stabilized, self-balanced, impact-resistant and the like;and thus, the bionic passive flexible low-energy-consumption ankle and foot prosthesis based on the rigid-flexible coupling is capable of perfecting natural-gait walking of an amputee, and improvingself-walking energy efficiency of the amputee.