The cathode system of conductive glass steel electric defroster can be used in the device for removing acid mist in the process that purifying the mercurial smoke in acid industry, belonging to the electric defroster area. The invention is formed by a cathode support beam, a cathode wire, a weight, and a lower cathode frame; wherein, the upper end of cathode wire is hanged on the cathode support beam, which is characterized in that the weight that connecting the lower end of cathode wire is formed by a sealed plastic outer cylinder and a inner lead weight; the lower cathode frame is formed by main beam and branch beam that made from plastic or glass steel; the branch beam has a hole adjusting plate; the weight outer cylinder is through the hole of said adjusting plate. In said system, lead weight inside the weight and the cathode wire are separated to effectively avoid the electric chemical erosion between them, and prolong the service life of cathode wire; the lower cathode frame has simple structure, high strength, and its hole adjusting plate make the position and distance adjustment of cathode wire easy; each cathode wire can be independently adjusted according to the shape of anode tube, with controllable size accuracy, lower weight, and easy installment; the electric field inside the conductive glass steel electric defroster is stable, with long service life, high defrosting efficiency and the acid mist outlet is not more than 3mg/NM3.