The invention discloses a novel arch-shaped plate and nail system for fixing and connecting bones. The system includes a bone connecting plate which is provided with five convex parts, and the five convex parts comprise two tail-end arch-shaped nail placing blocks, two half-width arch-shaped nail placing blocks and a fracture-area convex nail placing groove which are sequentially arranged from the tail end to the center; a certain included angle is formed between the nail placing surface of each convex part and the plane of the bone connecting plate, and a plurality of fixing holes are formed in the nail placing surfaces of the five convex parts respectively; by arranging multiple automatic locking and fixing nails of the fracture-area convex nail placing block to conduct fixation on the upper and lower ends of the fracture area through screws, the nail tips of the automatic locking and fixing nails are remained inside the broken bone; multiple threaded holes are formed in the bone connecting plate in a staggered mode, and the inner side of the bone connecting plate is in an arc shape and forms an inwardly-concave arc surface fitted with the broken bone. The novel arch-shaped plate and nail system for fixing and connecting the bones has the advantages of solving the difficulties that in the prior art, stability of bone connecting plates is poor, service life is short, safety performance is deficient, and secondary damage is likely to occur during inner fixation, and achieving effective protection on broken bone portions and fracture portions.