Evacuation stair of half-range traffic tunnel

The invention relates to the technical field of tunnel evacuation stairs, and discloses an evacuation stair of a half-range traffic tunnel, which comprises a first half-range tunnel and a second half-range tunnel, one side of the first half-range tunnel is provided with an overhanging space, both sides of the first half-range tunnel are provided with supporting structures, and the bottom of the first half-range tunnel is provided with a tunnel middle wall evacuation door. One end of a bottom foundation of the tunnel middle wall emergency door is fixedly connected with a steel ladder step, the top end of the steel ladder step is fixedly connected with a steel ladder protection cage, one side of the steel ladder protection cage is connected with the ground through the steel ladder step, and when a disaster occurs during first half-range tunnel construction, constructors in a tunnel can enter the tunnel middle wall emergency door, so that the tunnel middle wall emergency door is protected. According to the steel