An antenna line protection device includes a pair of coaxial connectors and a streamer discharge module. The pair of coaxial connectors are disposed on both side ends of the antenna line protection device. The streamer discharge module is coupled between the coaxial connectors so that, when a pulse signal is input via the coaxial connectors, the streamer discharge module induces an electric field and thus establishes a discharge current channel, thereby suppressing an excessive input pulse.