"My god, I’m a world champion!" said Cheong who came first with 397.50 points.
"I hoped for a medal, but I didn't think I could beat the Chinese divers," she said.
China's Si Yajie took silver just behind the Malaysian with 396.00 points.
"Cheong's win is a little surprise for me, but I congratulate her," she said.
Si's compatriot and reigning Olympic champion Ren Qian, who won silver in the event in 2015, took bronze (391.95).
Chinese divers have long dominated this event at world championships, winning 22 medals, 16 more than any other country.
Kim Kuk Hyang of North Korea, who won gold in 2015, came fourth with 388.55.