20mm UHMWPE 12-strand braided rope is used for the top support rope, with fiber strength of 37.2g/D or above and breaking strength of 35t. It is formed into a tic-tac-toe cross with cross 8 knots at the cross several times. The fixed vertical outline of the cage is made of 16mm UHMWPE 12-strand braided rope with a breaking strength of 20t. The mesh coat is made of warp knitted knotless mesh, 1600D/10 strands, wire diameter 2mm, mesh 35mm, 17.5mm×17.5mm square mesh assembly. The breaking strength of the mesh is 180kg or more.