Cold-proof bridge for double-layer steel roof panel

The utility model discloses a double-layer steel roofing board cold-proof bridge which comprises a lower layer steel roofing board, a heat preservation board and a top steel roofing board which are sequentially arranged from bottom to top, a layer of damp-proof veneer is further laid on the bottom side of the heat preservation board, and a cold-proof bridge purline is arranged between the lower layer steel roofing board and the damp-proof veneer. A heat insulation cushion block is arranged on the bottom side of the anti-cold-bridge purline in a cushioned mode, and the anti-cold-bridge purline corresponds to the panel steel purline on the bottom side of the lower-layer steel roof panel and is fixedly connected with the panel steel purline through an anti-cold-bridge fixing piece. A fixing support used for fixing the top steel roof panel is arranged between the top steel roof panel and the anti-cold-bridge purline, and a screw of the fixing support penetrates through the damp-proof veneer to be fixedly connecte