A Czochralski single crystal furnace for preparing monocrystalline silicon, comprising: a reaction chamber, and a first heat-preserving barrel and a second heat-preserving barrel respectively arranged around the reaction chamber, wherein: a side wall of the first heat-preserving barrel is provided with a first opening, an axial direction of the first heat-preserving barrel is the same as an axial direction of the second heat-preserving barrel, and one of the first heat-preserving barrel and the second heat-preserving barrel is arranged around the other of the first heat-preserving barrel and the second heat-preserving barrel; the Czochralski single crystal furnace has a first operation state and a second operation state, and the Czochralski single crystal furnace is configured to be switchable between the first operation state and the second operation state; wherein, in response to the Czochralski single crystal furnace being switched between the first operation state and the second operation state, the first heat-preserving barrel moves relative to the second heat-preserving barrel; in response to the Czochralski single crystal furnace being in the first operation state, a side wall of the second heat-preserving barrel is configured to cover the first opening so as to isolate the reaction chamber from an outside of the Czochralski single crystal furnace; and in response to the Czochralski single crystal furnace being in the second operation state, the second heat-preserving barrel is configured to expose the first opening, so that the reaction chamber is communicated to the outside of the Czochralski single crystal furnace through the first opening. a reaction chamber, and a first heat-preserving barrel and a second heat-preserving barrel respectively arranged around the reaction chamber, wherein: a side wall of the first heat-preserving barrel is provided with a first opening, an axial direction of the first heat-preserving barrel is the same as an axial direction of the second heat-preserving barrel, and one of the first heat-preserving barrel and the second heat-preserving barrel is arranged around the other of the first heat-preserving barrel and the second heat-preserving barrel; the Czochralski single crystal furnace has a first operation state and a second operation state, and the Czochralski single crystal furnace is configured to be switchable between the first operation state and the second operation state; wherein, in response to the Czochralski single crystal furnace being switched between the first operation state and the second operation state, the first heat-preserving barrel moves relative to the second heat-preserving barrel; in response to the Czochralski single crystal furnace being in the first operation state, a side wall of the second heat-preserving barrel is configured to cover the first opening so as to isolate the reaction chamber from an outside of the Czochralski single crystal furnace; and in response to the Czochralski single crystal furnace being in the second operation state, the second heat-preserving barrel is configured to expose the first opening, so that the reaction chamber is communicated to the outside of the Czochralski single crystal furnace through the first opening. a side wall of the first heat-preserving barrel is provided with a first opening, an axial direction of the first heat-preserving barrel is the same as an axial direction of the second heat-preserving barrel, and one of the first heat-preserving barrel and the second heat-preserving barrel is arranged around the other of the first heat-preserving barrel and the second heat-preserving barrel; the Czochralski single crystal furnace has a first operation state and a second operation state, and the Czochralski single crystal furnace is configured to be switchable between the first operation state and the second operation state; wherein, in response to the Czochralski single crystal furnace being switched between the first operation state and the second operation state, the first heat-preserving barrel moves relative to the second heat-preserving barrel; in response to the Czochralski single crystal furnace being in the first operation state, a side wall of the second heat-preserving barrel is configured to cover the first opening so as to isolate the reaction chamber from an outside of the Czochralski single crystal furnace; and in response to the Czochralski single crystal furnace being in the second operation state, the second heat-preserving barrel is configured to expose the first opening, so that the reaction chamber is communicated to the outside of the Czochralski single crystal furnace through the first opening.