Modular ceiling joist structure

The utility model relates to the technical field of ceiling joist structures, in particular to a modular ceiling joist structure. According to the technical scheme, the connecting structure comprises a main beam and a branch beam, the upper surfaces of the two ends of the main beam are each fixedly connected with a pair of first connecting pieces, and the two ends of the branch beam are clamped between the two corresponding first connecting pieces and fastened through bolts; the ends of every two adjacent collinear main beams are fixedly connected through a second connecting piece, and inserting grooves matched with the ends of the main beams are formed in the two ends of each second connecting piece. Through the design of the second connecting pieces and the third connecting assemblies, the adjacent main beams and the adjacent branch beams can be connected with each other, so that a traditional whole long steel bar is divided into a plurality of short section steel, modular assembly of the ceiling joist is a