The utility model discloses a fixed subassembly of restrainting that tree tomato grafting used, including fixed outer pole, fixed interior pole, compression spring, fixture block, fastening bolt, elasticity knee, arc splint, connecting rod, U -shaped clamp splice, screwed pipe, clamping screw, bearing, telescopic screw rod, fixed band and plastic strip. The beneficial effects of the utility modelare that: the pole moves in fixing outer pole through being used in of telescopic screw rod in fixed, and to the compression spring compress in the pole in fixed, it is more stable with being connected of fixed interior pole to make fixed outer pole, the arbitrary department of pole outside fixed is laid to the fixture block, and it is fixed by fastening bolt, make the arc clamp of fixture block upper end accurately lay at the grafting position, the inboard of arc splint is equipped with ventilative rubber pad, thereby avoid the relatively poor growth that influences the grafting plant of grafting position gas permeability, the fixed band is elastic cloth belt, and the junction at both ends is equipped with sticking stripe, make the fixed band stretch, so that provide stronger fixed power,still make things convenient for workman's ligature and disassemble.