The utility model provides a repeatedly usable's pre -buried lead screw subassembly for support the truss of unilateral steel form among the building engineering, including pre -buried lead screw in the concrete of bottom, with truss connection's oblique wire drawing pole, and the first connecting piece that links together pre -buried lead screw and oblique wire drawing pole, the bottom of pre -buried lead screw is equipped with the crotch. The utility model discloses a pre -buried lead screw subassembly when single -side supporting formwork is under construction, links together pre -buried lead screw and oblique wire drawing pole through first connecting piece, and the atress effect is the same with single rhizoid pole, and the realization is to the strong support of steel form truss. The back is accomplished in the construction, demolishs steel form panel and truss, loosens first connecting piece, takes out oblique wire drawing pole, and oblique wire drawing pole can used repeatedly, resources are saved.