You should prepare enough cash. Both dollars and pounds can be exchanged to Chinese yuan through the Bank of China or other big banks. But please don't take too much cash with you. It's not a wisdom action. Traveler's Cheque will be very helpful. If your credit card can be used in China, it would be better. To know more, you can read the following page:

https://www.travelchinaguide.com/essential/money-matter.htm