A prosthetic foot, comprising a forefoot carbon fiber curved plate, a heel carbon fiber curved plate, a connection assembly, a first fastening assembly, a second fastening assembly, a third fastening assembly, an upper connection base and a square cone joint, wherein the forefoot carbon fiber curved plate and the heel carbon fiber curved plate form a longitudinal arch shape, and the forefoot carbon fiber curved plate forms a transverse arch shape characterized in that: the square cone joint of the connection assembly is disposed in a square shallow recessed groove of the upper connection base in the connection assembly and is connected by the first fastening assembly, a center of the square cone joint is provided with a stepped hole, the first fastening assembly is penetrated in the stepped hole; a first arc side wing of the upper connection base in the connection assembly, the forefoot carbon fiber curved plate, the heel carbon fiber curved plate and a lower abutting plate in the connection assembly are fixedly connected by the third fastening assembly; and a second arc side wing of the upper connection base in the connection assembly, the forefoot carbon fiber curved plate, the heel carbon fiber curved plate and the lower abutting plate in the connection assembly are fixedly connected by the second fastening assembly. wherein the forefoot carbon fiber curved plate and the heel carbon fiber curved plate form a longitudinal arch shape, and the forefoot carbon fiber curved plate forms a transverse arch shape characterized in that: the square cone joint of the connection assembly is disposed in a square shallow recessed groove of the upper connection base in the connection assembly and is connected by the first fastening assembly, a center of the square cone joint is provided with a stepped hole, the first fastening assembly is penetrated in the stepped hole; a first arc side wing of the upper connection base in the connection assembly, the forefoot carbon fiber curved plate, the heel carbon fiber curved plate and a lower abutting plate in the connection assembly are fixedly connected by the third fastening assembly; and a second arc side wing of the upper connection base in the connection assembly, the forefoot carbon fiber curved plate, the heel carbon fiber curved plate and the lower abutting plate in the connection assembly are fixedly connected by the second fastening assembly. the square cone joint of the connection assembly is disposed in a square shallow recessed groove of the upper connection base in the connection assembly and is connected by the first fastening assembly, a center of the square cone joint is provided with a stepped hole, the first fastening assembly is penetrated in the stepped hole; a first arc side wing of the upper connection base in the connection assembly, the forefoot carbon fiber curved plate, the heel carbon fiber curved plate and a lower abutting plate in the connection assembly are fixedly connected by the third fastening assembly; and a second arc side wing of the upper connection base in the connection assembly, the forefoot carbon fiber curved plate, the heel carbon fiber curved plate and the lower abutting plate in the connection assembly are fixedly connected by the second fastening assembly.