You mean train ticket, right? You can go to the Haikou Railway Station in Wuhan to buy it in advance. The Train T192 from Hankou to Urumqi leaves at 19:10. It takes about 39 hours to get to Urumqi. I suggest you purchase an hard sleepper ticket. The soft sleeper ticket is better. The ticket cost is as follows:
hard seat: CNY351
soft seat: CNY557
hard sleeper: CNY589/610/631
soft sleeper: CNY930/972
You should purchase the ticket as soon as possible in case the tickets are sold out.