ABOUT CLOUDFLARE CDN
Cloudflare’s content delivery network (CDN). Cloudflare caches content across a global network and integrates with a wide range of other technologies to provide a CDN that is “easy to setup, [and] more affordable”.
Issues with Cloudflare CDN in China
CDNs perform a variety of functions, the most traditional being accelerating the "delivery of content". The primary reason sites don’t ‘work’ in China is due to compatibility issues, which CDNs are unable to fully address.