Box hollow anti-floating device and method for cast-in-situ concrete hollow floor

The invention relates to a box hollow anti-floating device and method for a cast-in-situ concrete hollow floor. The box hollow anti-floating device comprises a glass fiber reinforced composite box, board surface rebars, board bottom rebars, a pouring formwork and anti-floating iron wires, wherein the glass fiber reinforced composite box is placed in the pouring formwork; the board surface rebars are arranged on the glass fiber reinforced composite box; the board bottom rebars are arranged under the glass fiber reinforced composite box; and the anti-floating iron wires are fastened on intersection points of the board bottom rebars at intervals of 0.6-0.8 meter, penetrate in the pouring formwork and are anchored on the pouring formwork. By the box hollow anti-floating device, correctness of longitudinal and transverse distances of internal molds is guaranteed, floating of the internal molds is controlled, and the circumstance that the internal molds drive a bottom reinforcing mesh to float can be prevented.