TL;DR: Technically personal VPN usage is banned in China, but it would be very unlikely to run into trouble for using it.
Legitimate uses for VPNs in China
The Chinese government allows embassies and large multinational companies to access VPN services. These entities then use VPN services from state approved ISPs, which cost multitudes more than private VPN services.
In July, 2017, during a round of VPN crackdowns, the Chinese government blocked the Embassy of France’s VPN line. This furthermore proves that legitimate and illegitimate VPN have not yet been recognised by the Chinese government.
Choose VPN Services That Are Located Outside of Mainland China
VPN services that have headquarters in other countries are more reliable as they are not subject to the rules and regulations of the People’s Republic of China.
The Chinese Government Knows People Will and Are Using VPNs to Circumvent the Great Firewall
You can say that VPN usage in China runs rampant is an unexpected effect of implementing the “Great Firewall of China.” The officials know that people need to access outside information and services such as Google’s products, social media, porn, news, etc.