Since you are a US citizen and live in the US, no issues about you being a sponsor. Regarding your fiance' using the US consulate in Guangzhou, the key issue will be his status in China. I would advise him to contact the consulate and tell them his visa classification in China. They can make the determination whether they will entertain his K-1 visa locally or not. If yes, then everything thing should be set for you both. If not, he will need to get his K-1 from Algiers.
Good luck!!!