The utility model provides a
cutting device which comprises a support,
a diamond wire, a positioning part connected with the support, a
gear train mechanism and a motor. The positioning part is used for abutting against a horizontal positioning surface of a
thermal insulation cylinder of the
single crystal furnace; the
wheel train mechanism at least comprises a driving wheel and a driven wheel, and the driving wheel and the driven wheel rotate around the
vertical axis relative to the support. The
diamond wire is arranged on the
wheel train mechanism in a surrounding mode, and under the condition that the positioning part abuts against the horizontal positioning face, the
diamond wire can be not lower than the top face of the heat preservation
barrel. The motor is used for driving the driving wheel to rotate so as to drive the
diamond wire to move, and the diamond wire can
cut the heat preservation felt. According to the
cutting device, the diamond wire is used for
cutting the heat preservation felt, the heat preservation felt is not prone to deformation in the cutting process, the matching relation of the positioning part and the horizontal positioning face can play a limiting role, it is guaranteed that the cutting part is always located at the same height level in the cutting process, the edge of the
cut heat preservation felt is neat, and the cutting efficiency is improved. And therefore, the adjacent heat preservation felts are tightly butted.