The invention discloses a ceiling building material structure convenient to assemble. The ceiling building material structure comprises a plurality of ceiling modules, a plurality of keels, first connecting pieces and second connecting pieces. The ceiling modules are connected through the first connecting pieces. The keels are connected through the second connecting pieces and enable the first connecting pieces to be transversely or longitudinally connected in series. The edges of the ceiling modules are provided with inward concave connecting grooves. The ceiling building material structure has the beneficial effects that a ceiling adopts a modularized system and can be freely assembled into needed sizes, and by adoption of assembly between the modules and the connecting pieces, dismounting is convenient, meanwhile, the strength of the ceiling can be improved by adoption of the keels, a dark chamber is further formed and used for wiring concealed wires on the ceiling, and use is convenient.