Is it illegal to steal drinks from the buffet?

Break the law. According to Article 264 of the Criminal Law of People's Republic of China (PRC), whoever steals public or private property in a relatively large amount, or who steals repeatedly, burglary, theft with a weapon or pickpocketing, shall be sentenced to fixed-term imprisonment of not more than three years, criminal detention or public surveillance, and shall also, or shall only, be fined. Buffet means that diners can choose and enjoy whatever they like within a given range, regardless of quantity and time.