The highest operating temperature of ceramic fiber refers to the limited temperature ceramic fiber can bear within short time, which represents ceramic fiber products heat resistance index. Ceramic fiber products allowed long time temperature is generally around 200℃ lower than the highest use temperature. Take domestic 1260℃ fiber products, for example, its long using temperature is 1000℃. Therefore, the highest temperature concept is very important, which has close relation with the long time using temperature and is applied in the process of fiber main reference basis. In the past, some people take the highest temperature as a long-term use of temperature, which is wrong and will cause unnecessary loss.