The utility model discloses a rail traffic signal lamp with protecting sheathing, including cement pier, the connecting plate, the pillar, the protecting sheathing body, the door body, the signal lamp body, transparent glass window, the hollow case that holds, the hollow incasement that holds is filled and to be had nitrogen gas and dry powder fire extinguishing agent, the hollow top that holds the case is fixed with an applying powder section of thick bamboo and inflation inlet, there is a lid at the top of an applying powder section of thick bamboo through threaded connection, install one -way air inlet valve on the inflation inlet, the hollow bottom that holds the case be provided with with the hollow flame projecting barrel that holds incasement chamber intercommunication, the left and right sides that the hollow bottom that holds the case is located the flame projecting barrel is fixed with a jib respectively, the bottom of two jibs is connected through horizontal seat, the bottom of flame projecting barrel is provided with the sealed lid of activity for the bottom activity of opening and flame projecting barrel, the top of horizontal seat is connected with through a vertical thrust unit places the seat, it is provided with temperature -sensitive glass ball to place between the sealed lid of seat and activity. The beneficial effects are that: has the function of putting out a fire.