Building construction protective net

The utility model relates to the field of building guardrails, in particular to a building construction protective net which comprises a protective frame, first vertical columns are arranged on the left side and the right side of the outer wall of the protective frame, L-shaped connecting pieces are welded to the sides, close to the protective frame, of the first vertical columns, and penetrating openings are formed in the surfaces of transverse pieces of the L-shaped connecting pieces. And screws are mounted at the penetrating holes. According to the building construction protective net, the rotating shaft is controlled to rotate, a first conical tooth column and a second conical tooth column which are fixed to one end of the rotating shaft are meshed, a lead screw fixed to the bottom of the second conical tooth column is in threaded connection with a lead screw barrel, the lead screw barrel is fixed to a sliding block through a welding rod, and the sliding block is in sliding connection with a sliding groov