Disclosed is a cast-in-situ concrete hollow slab, which comprises a reinforced-bar concrete (1) and shuttering members (2), the shuttering member (2) is enclosed in the reinforced-bar concrete (1), the shuttering members (2) are arranged alternatively, a cast-in-situ reinforced-bar concrete rib (3) is arranged between them, and a cast-in-situ
reinforced concrete upper slab (4) is arranged above, a cast-in-situ
reinforced concrete upper slab (5) is arranged below, the shuttering members (2) comprise an upper board (6) and
peripheral side panels (7), the upper board (6) and the
peripheral side panels (7) encloses an open basin shape component, characterized in that an upper board
dormer window (56) is arranged on the upper board of the basin form component at a central portion,
dormer window walls are extended upwards from the edges of the upper slab
dormer window (56), thereby forming a section of short
pipe hole provided with a cover board (63). The invention can be applied to cast-in-situ
reinforced concrete or prestressed reinforcement concrete's hollow storied-building roofings, house roofings, walls, foundation bedplates and hollow bridges, especially for hollow flat slabs.