The ticket I bought is from Kashgar to Changsha, but there is only 70 minutes to catch up when I have to transfer to Changsha in Xi'an?

It is not too late (early flights are usually not late), it is recommended to buy a connecting ticket, even if the first flight is late, you can change the second flight ticket for free...<br/><br/>Help you, please click the green [Accept] !

If it is not a joint ticket, it is recommended not to make such a transit combination, in case the previous flight is delayed, it will easily cause economic losses. If it is a joint ticket, you can try it. After all, if there is a problem with the joint ticket in transit, the airline will be responsible. (for reference only)