Steel structure civil air defense door leaf and machining process thereof

The invention relates to a steel structure civil air defense door leaf. The steel structure civil air defense door leaf comprises a frame, a reinforcing steel bar net, a front door plate and a rear door plate, wherein the front door plate is fixed to a front end of the frame, the rear door plate is fixed to a rear end of the frame, the reinforcing steel bar net is fixed in the frame, and a closed buffer cavity is defined by the frame, the front door plate and the rear door plate; the buffer cavity is formed in the front door plate, a separation net is arranged in the middle of the buffer cavity and divides the buffer cavity into a first cavity body and a second cavity body, the first cavity body is arranged between the front door plate and the separation net, anti-rust layers are arranged on a side wall of the buffer cavity, a surface of the reinforcing steel bar net and a surface of the separation net, the first cavity body is filled with energy absorption blocks, a gap between the second cavity and the ener