The subway fire-resistant air duct cold proof bridge is provided with aluminum silicate wool or fireproof board as the thermal insulation and fireproof layer (40~60mm), galvanized steel sheet (0.6~2.0mm) of different thickness is used inside and outside, and the cold proof bridge angle steel flange is selected. The fire resistance time is 30min, 60min, 90min, 120min, 180min