The utility model discloses a box mills with clamping apparatus about gearbox, including the bottom plate the left and right sides of bottom plate is provided with at least a set of fixed establishment respectively, fixed establishment includes first mount pad, second mount pad and pressing plate frame, first mount pad is fixed with the second mount pad on the bottom plate, pressing plate frame's one end pass through the connecting pin with first mount pad rotates to be connected, pressing plate frame's middle part wears to establish on the screw rod that second mount pad top is connected, be provided with adjusting nut at the top of this screw rod, a connecting rod is worn to be equipped with by pressing plate frame's the other end be connected with an at least clamp plate on the connecting rod the bottom plate of clamp plate below has set firmly two at least spinal branch daggers. It is showing the effect: can be quick load and unload the part to the machining precision can obtain guaranteeing, puies forward high pressure heater work efficiency rate greatly.