The present invention relates to a small enclosure-type branch binding machine comprising a clamping device, a bow-shaped frame, a handle, a machine frame, a needle box and a strap box. The handle and bow-shaped frame are hinged on the machine frame in an "X" shape. The clamping device at the front end of the bow-shaped frame includes a hook head with a pressing block and a top block, equipped with a torsion spring and a compression spring. A single compression spring realizes both driving and locking functions of the hook head, significantly reducing production cost and machine head size while avoiding damage to plants during branch binding.