I am starting a Northern Soul night in Chengdu, China. Does anyone know what the PRS situation is? I'd be grateful for any advice or referrals. Cheers.

Normally PRS is covered and where relevant paid in the country of the performance unless there is a partnership arrangement with another country to collect it.

This page sets out all the arrangements between UK including the one with China:

https://www.bmi.com/international/entry/reciprocal_representation_agreements_foreign_performing_rights_societies

The Chinese PRS equivalent details including direct email and phone numbers are at:

https://www.ifrro.org/members/music-copyright-society-china

Their main page is at:

https://www.mcsc.com.cn/

It may be worth a quick call to PRS in UK who through their partnership with China's body may be able to give a bit of advice.