Fabricated building roof structure

The utility model provides an assembly type building roof structure which comprises a cross beam, a supporting assembly is arranged on the outer surface of the cross beam and comprises a supporting frame, the supporting frame is movably installed on the outer surface of the cross beam, one end of a supporting rod is fixedly connected to the surfaces of the left end and the right end of the supporting frame, and a first connecting assembly is arranged at the bottom of the cross beam. The first connecting assembly comprises a connecting rod, the connecting rod is movably installed at the bottom of the cross beam, the clamping block is movably embedded in the cross beam and the supporting frame, a rotating assembly is arranged in the cross beam, the rotating block is fixedly installed on the outer surface, close to the bottom, of the clamping block, and a rotating sleeve is movably connected to the outer surface of the rotating block; the outer surface, close to the bottom, of the clamping block is movably embed