The utility model provides a high-strength steel swing plate wave-absorbing protective door which is arranged in an underground railroad civil air-defense construction ventilation duct. The high-strength steel swing plate wave-absorbing protective door comprises a steel door leaf, a steel door frame, a steel lock, a steel hinge and a door leaf fixing device. A rubber pad is arranged between the steel door leaf and the steel door frame, a ventilation hole is formed in the steel door leaf, and the windward face of the steel door leaf is provided with a high-strength steel swing plate movable door corresponding to the ventilation hole. The high-strength steel swing plate movable door comprises a steel movable door base, a steel movable door base hinge seat, a steel hinge shaft, a high-strength steel swing plate hinge seat, a high-strength steel swing plate and a steel limit seat. The high-strength steel swing plate wave-absorbing protective door is simple in installation, solves the problem that in the prior art, a rail traffic cleaning type ventilation system needs a long civil engineering protection segment in the axial direction, saves civil engineering cost of projects, and has the advantages of being simple in operation, flexible in opening and closing, and convenient to use and maintain.