Can I transfer my hukou to Xinjiang in senior three?

You may not be able to do it in the third year of high school unless there is a big back door, because in order to prevent immigrants like you from entering the college entrance examination, candidates must study in Xinjiang for more than two years, which means that you went to Xinjiang for two years before the college entrance examination. If you transfer back now, you may repeat the grade, in order to meet two years.