Can I use iphone 14 in China

If you bought the phone in the USA, it only has eSIM. See About eSIM on iPhone - Apple Support

"eSIM on iPhone is not offered in China mainland. In Hong Kong and Macao, some iPhone models feature eSIM. Learn about using Dual SIM with two nano-SIM cards in China mainland, Hong Kong, and Macao. For travelers visiting China mainland who wish to use an eSIM for prepaid data plans, these are offered by many worldwide service providers. "

Also of interest:

Find the iPhone that’s right for your country or region. - iPhone - Supported 5G and LTE networks - Apple

If it is a US iphone 14, and you have a US carrier you will be using for roaming in China, yes. You will not be able to use any Chinese carrier on a US iphone 14. The US iphone is eSIM only and eSIMs are not supported by the Chinese carriers.

All models of the iphone 14 sold outside of the US can accommodate a physical SIM card, which would be required if you wish to use a Chinese cellular carrier.