People's air defense project: people's air defense project, also known as people's air defense fortification, refers to the protection of wartime personnel and materials shelter, people's air defense command, medical rescue and separately constructed underground protective buildings, as well as combined with the ground building construction of wartime can be used in the basement of the air defense. People's air defense project is to guard against sudden attacks by the enemy, effective sheltering of personnel and materials, save the war potential of the important facilities; is to adhere to the town fighting, long-term support for the anti-invasion war until the victory of the engineering security.