A self-healing method for fractured single crystal SiC nanowires. A hair in a Chinese brush pen of yellow weasel's hair moves and transfers nanowires, which are placed on an in-situ TEM mechanical microtest apparatus. An in-situ nanomechanical tension test is realized. The nanowires are loaded. Displacement is 0-200 nm. Fracture strength of the single crystal nanowires is 12-15 GPa. After the nanowires are fractured, unloading causes slight contact between the fractured end surfaces, electron beam is shut off, and self-healing of the nanowires is conducted in a vacuum chamber. Partial recrystallization is found at a fracture after self-healing through in-situ TEM representation. A fracture strength test is conducted again after self-healing. A fractured position after healing is the same as the position before healing. The fracture strength of the single crystal nanowires after self-healing is 1-2.5 GPa. The recovery ratio of the fracture strength is 10-20%.