The invention discloses a floor slab filling body which comprises a honeycomb core body. The honeycomb core body is formed by splicing two parts, the parts are both in shapes of slot bodies, and the two parts are spliced and joined through the slot ends; a connecting body is further included, serves as a constraint member of relative positions of the two parts and is used for realizing fixation ofthe relative positions of the two parts; an annular groove formed in the outer side of the honeycomb core body is also included, the annular groove extends along the side face of the honeycomb core body. The filling body is convenient to manufacture; meanwhile, anti-floating constraints are easy to achieve; and in addition, no impact on other construction items of floor slabs or floor systems iscaused.