The utility model provides a novel gas discharge tube for coaxial cable belongs to and prevents the lightning stroke overvoltage technical field field, including cylindrical cavity, the cavity comprises the end cap at cavity wall and upper and lower both ends, is provided with inert gas in the cavity, wherein, radially is provided with the electrode in the cavity, and the both ends of electrode are passed the end cap at upper and lower both ends respectively and are connected with the sinle silk of the coaxial cable at both ends, the cavity wall is by inlayer, skin and be located inside filler and constitute, be provided with the bump on the electrode. The beneficial effects of the utility model are that: using this gas discharge tube, can concatenating in the coaxial transmission line cable, can reach higher transmission frequency bandwidth, the loss is lower, and thunder and lightning discharge capacity is big, and protection voltage is more excellent, safe and reliable's characteristics.