The invention relates to a single-solenoid single-pole double-throw coaxial switch. The single-solenoid single-pole double-throw coaxial switch is characterized by comprising a shell, binding posts, an iron core, a coil, a cover plate, joints, outer conductors, an armature assembly and spring plate assemblies, wherein a cavity is formed below the shell; the binding posts are mounted above the shell; the lower part of the interior of the shell is fixedly connected with the cover plate; the armature assembly is rotatably connected with the cover plate; the iron core is arranged on the right sideof the armature assembly; the coil sleeves the outer side of the iron core; the spring plate assemblies are arranged on the left side and the right side of the lower part of the armature assembly; the armature assembly is used for driving the spring plate assemblies to be in contact with the joints; the joints are positioned inside the cavity; the joints are connected with the outer conductors; and the outer conductors are fixedly connected with the shell. According to the single-solenoid single-pole double-throw coaxial switch, a novel relay design is adopted, only one coil is used, the structure is simpler, the assembly efficiency is higher, and simultaneously, the cost is reduced; and a failure protection type design is adopted, so that the normal position can be restored during powerfailure.