The invention discloses a building construction protective window device. The building construction protective window device comprises a base, wherein two ends of the base are separately hinged to twostand columns through hinged shafts, the stand columns can rotate to the inner side of the base through the hinged shafts, baffles are separately arranged at two ends of the base, the baffles are perpendicular to the base, plug-in grooves are separately formed in the tops of the stand columns, plug-in columns are arranged at two ends of a winding drum, the plug-in columns can be inserted into theplug-in grooves, a protective net is wound on the winding drum, a plurality of hooks are arranged on the side edge of the protective net, and a corresponding number of hanging rings are arranged at the position, corresponding to the hooks, of the base. According to the building construction protective window device, through the arrangement of the base and the stand columns, the stand columns canbe rotated to a folded state with the base or perpendicular to the base, so that installation and disassembling are convenient; when a protection window needs to be installed, the stand columns are ina perpendicular state with the base, the winding drum is horizontally placed on the stand columns, and the protective window device can be formed by lowering the protection net from the winding drum;and when disassembling is required, the protection net is wound on the winding drum, the winding drum is moved down, and the stand columns and the base are recovered.