Crucible preparation method, crucible and single crystal furnace

The invention provides a preparation method of a crucible, the crucible and a single crystal furnace, and relates to the technical field of monocrystalline silicon preparation. The preparation method of the crucible comprises the following steps: arranging the carbon source on the outer wall of the crucible body; in an oxygen-free environment, a crucible body with a carbon source arranged on the outer wall is heated to a first preset temperature, so that the carbon source on the outer wall of the crucible body chemically reacts with silicon dioxide in the crucible body, and an isolating layer located on the outer wall of the crucible body is generated; and the isolating layer comprises the following components: silicon nitride and/or silicon carbide. In the crystal pulling process, silicon dioxide in the crucible body can be physically isolated from carbon in the crucible side through the isolation layer, loss of the crucible side can be avoided, and the isolation layer is located on the outer wall of the cru