BA / Avios has no domestic Chinese partners, so you would not be able to redeem for internal Chinese flights without connecting in HKG or some other external airports.

Do note that while CX imposes surcharges, in my experience, it tends to be more reasonable for regional flights (around $40 - $60 USD), so while connecting in HKG is not ideal in terms of schedule, it may not be a bad value in terms of mileage and surcharges required.