Flight HX115 was en route to Hong Kong from Hangzhou when the incident happened.
Passengers on board the flight shared videos on social media, showing cabin crew and passengers pouring bottles of water onto a bag in an overhead compartment, from where smoke was billowing.
It’s believed a portable charging device had triggered the fire.
Hong Kong Airlines said in a statement that the blaze has been put out, and that its providing assistance to passengers and crew members.