The utility model relates to an insulation assembly for a nuclear fusion reactor and particularly relates to the insulation assembly for insulation between a direct current glow electrode and a vacuum chamber device wall for the nuclear fusion reactor. The insulation assembly comprises a nut, a cover cap, a concave and convex type concentric ring gasket, flat type concentric ring gaskets having different drift diameters, an electrode fixing board, a fixing bolt, a concave and convex type concentric ring gasket having a sleeve structure and the vacuum chamber device wall, wherein the concave and convex type concentric ring gasket having the sleeve structure, the electrode fixing board, the flat type concentric ring gaskets having different drift diameters, the concave and convex type concentric ring gasket and the cover cap are sequentially stacked and sleeved on the fixing bolt, one end of the fixing bolt is equipped with the nut used for fastening a ceramic insulation member and the electrode fixing board, and the other end of the fixing bolt is connected with the vacuum chamber device wall. The insulation assembly directly determines a processing effect of the nuclear fusion vacuum chamber device wall, and plasma discharge quality is further determined. The insulation assembly is especially applied to a Tokamak device in a nuclear fusion vacuum chamber, a first wall of the Tokamak device is equipped with graphite, and fiber is used.