The utility model discloses a roof beam rebar installation instrument, two supporting seats including the symmetry setting to and set up two facing to the several connecting rod in the middle of the symmetrical supporting seat that sets up, the support stationary ladle draw together upper strut (4) and lower part and support (5), upper strut (4) and lower part support (5) and fix through the steel sheet was worn in with to two steel sheet (8) centre grippings bolt and nut device (6), upper strut (4) be a steel sheet, be provided with bow -shaped dashpot (7) and anti -skidding pole (2) in upper strut (4), upper strut (4) both ends be provided with connecting hole (3), both sides are provided with locating hole (1). The utility model provides a quality problems that exist in the on -the -spot frame roof beam construction, and the waste material at this usable scene of utility model preparation, with low costs and simple manufacture, swift. The utility model discloses a convenient operation, sturdy and durable, the roof beam of applicable and various deck -moldings is worth using widely.