Wire snapping device for building construction

The utility model discloses a line snapping device for building construction, which comprises a line snapping box, an ink storage box is arranged on one side of the line snapping box, two rotating rods are arranged in the line snapping box, the surfaces of the two rotating rods are respectively connected with a first elastic line and a second elastic line, one end of the first elastic line is connected with a pull rod, and the second elastic line is connected to the surface of the pull rod. One end of the rotating rod is provided with a limiting piece, one end of the limiting piece is connected with a torsion spring, one end of the torsion spring is connected with a blocking piece, a connecting block is installed on the surface of the second elastic thread, an extrusion rod is installed in the connecting block, a fixing block is fixed to the surface of the extrusion rod, and C-shaped blocks are fixed to the two sides of the rear surface of the fixing block; the elastic thread I is connected inside the C-shape