The invention discloses an insulated fixing device for use in live replacement of a drop-out fuse. The insulated fixing device is simple in structure, a safe insulated working space can be provided for operating personnel, and an upper side lead and a lower side lead of the fuse are fixed at appropriate positions. According to the adopted technical scheme, the insulated fixing device comprises a fixing support rod and two insulated baffle plates, wherein a fixing part for fixing the whole fixing support rod on a mounting cross arm of a drop-out fuse to be replaced is arranged on the fixing support rod; a first support cross rod and a second support cross rod for fixing the upper side lead and the lower side lead of the drop-out fuse to be replaced are arranged at the two ends of the fixing support rod respectively; the two insulated baffle plates are provided with fixing holes for mounting the insulated baffle plates on the mounting cross arm of the drop-out fuse to be replaced. The insulated fixing device is suitable for electric power departments.