However, the 25-year-old isn't focusing only on himself.
He also has another big aim in life - trying to help troubled children tackle everyday problems such as school bullying by teaching them self-defence.
Li and his sanda master, Lau Siu-kwong, of the Pro Arts Sanshou Association, have been making weekly visits to coach troubled children at Christian Zheng Sheng College since 2009.
"Master Lau started it off and then I joined him," Li says, now in the last year of his psychology degree at Tung Wah College, in Ho Man Tin.
"It's a meaningful and really rewarding activity - showing children that the tears and sweat from doing something difficult will pay off in the end.
"We teach them self-defence. During sanda training in the ring, we show them methods of attack, so they can also experience what it's like to be hit during practice.
"They get to know what it's like for the victims who are bullied at school."
Sanda, which means "free fight", is the self-defence form of wushu, and a perfect sport to help children learn to protect themselves.
Yet few Hongkongers know much about sanda, also known as sanshou, Li says. It focuses on three major skills - kicking, punching and grappling; many people think it looks like a mixture of kickboxing, taekwondo and wrestling.
"It's a sport that requires you to stay really alert all the time. In a fight, you need to make split-second decisions," Li says.
As the sport is so intense, Li often suffers bruises and other injuries to his shoulders, thighs, knees and legs.
"This year's local movie, Unbeatable, about martial arts - starring Eddie Peng Yu-yen and Nick Cheung Ka-fai - stunned people with its scenes of tough training methods," Li says. "But I have to do much more difficult training every day."
Li says that he started doing sanda "for fun after taking his HKCEE. I soon realised it needs lots of commitment and effort; it's not only a sport, it's an attitude, too."
He says: "You must be determined to keep training; it's really mentally and physically demanding."
Wushu is one of the elite sports in Hong Kong, so athletes can train at the Hong Kong Sports Institute, in Sha Tin. But Li is the only member of the wushu team who practises sanda; all the other funded athletes practise the other discipline, taolu, focused on performing patterns.
It means Li must train alone - except for when special sessions are held before tournaments - with Lau, his sanda master. Li says he would be unable to keep competing without the support of Lau and the association.
"Hong Kong lacks an official training base just for sanda," Li says. "We use one centre at Lei Yue Mun Sports Centre, but need to share space with other users.
"Sometimes we have to find an empty area and train there, or even go to master's home."
Over the past few years Li has been improving his skills in sanda.
He won a bronze medal in the 56-to-60kg event at the East Asian Games, in Hong Kong in 2009; Li won the gold medal at this year's East Asian Games, in Tianjin .
He was eighth at the 2011 World Championships. But now, after his bronze medal at last month's World Combat Games, in Russia, he says he can win the 2015 world title, in Indonesia. "Standing with the gold medal round my neck as world champion is my goal," he says.