The utility model discloses an instrument style builder's jack bracing device, the kind of instrument style builder's jack bracing device stretch the nut by bracing piece, buckle stem stem, anticreep nut and top and cup joint and constitute. The bracing piece is hollow steel pipe, and the buckle stem stem cup joints with the bracing piece clearance, and the anticreep nut is stretched the nut with the top and is formed a complete set with the screw on the buckle stem stem. Earlier respectively at scaffold encorbelment girder steel top downside and lower floor's wall installation steel ring before the construction, stretch the nut with anticreep nut and top earlier during the construction and cup joint on the buckle stem stem, hold buckle stem stem wugou again and insert the bracing piece both ends, then hook the two steel ring on encorbelment girder steel and the wall respectively with bracing device both ends crotch to adjusting the anticreep nut and sealing the crotch fork, it is tight with bracing device top that the nut is stretched on the recaccommodation top, has accomplished the installation of builder's jack bracing device so promptly. The utility model discloses simple structure, the installation is convenient with the dismantlement, and can reach used repeatedly, material saving, reduction construction cost's purpose.