Protective doors of railway tunnel is an important branch of the tunnel disaster prevention and rescue project and has an important influence on safety. A novel innovative protective railway tunnel door based on the micro-structure fiber distributed sensor(MFDS) was studied in this paper, which could be used for the alarm system, the display and recording of alarm parts and alarm data, detection of operational failure and alarm signal remote transmission function. The following research results are reached: (1) the arrangement scheme of protective doors should be taken away from the center line of tunnel; (2) the partition wall of the protective door is made of beton; (3) the door should be opened in the direction of evacuation; (4) when designing the distance between the outside of protective door and central line of adjacent lines, we should consider the frame height of protective door and vehicle clearance. The research results can provide guidance for the design of protective doors for railway tunnel to a certain extent.