First, it's important to identify the cause of slow display speed, but it can be improved with the following methods.
1. Remove resources from domains such as Google and Facebook
Access at the domain level may be slow for access from China, so please check which domains are problematic.
2. Use a CDN
Even using a CDN for just images can make the load time faster.
3. Place servers or CDN edge servers in China
There is a method of placing servers or CDN edge servers in China, but there are ICP registrations, so please consult with a specialist on ICP registrations.