The present disclosure discloses a thermal plasma treatment method for sulfur hexafluoride (SF6) degradation. In the thermal plasma treatment method for SF6 degradation, Ar is input into a thermal plasma generator as a carrier gas; annular electrodes are electrically connected to a direct current power supply to generate an arc plasma region in the presence of the carrier gas Ar; to-be-reacted SF6 and to-be-reacted H2 in a predetermined ratio are input into the arc plasma region to generate hydrogen radicals as well as fluorine radicals, and the hydrogen radicals and the fluorine radicals are bonded with each other to generate HF to inhibit the self-recovery reaction of SF6; and final products include HF and elemental S.