The 27-year-old became the first Chinese athlete to ever win an Olympic snowboard medal with a silver in PyeongChang.
She decided to sit out the 2018/19 season but made her World Cup comeback at Copper Mountain last week with a silver.
However, she went better at Secret Garden with a superb second run scoring 90.80 points to beat last season's crystal globe winner Cai Xuetong and Maddie Mastro.
"I'm feeling pretty stoked," Liu said.
"First because it's awesome for me to win in China. I'm Chinese, and Secret Garden is kind of my home resort, and this competition is in the Olympic pipe. For me to win in China, I'm super happy. The pipe here is really good, and the wind is pretty steady so it doesn't really matter too much."
The win moves Liu to the top of the World Cup standings, ahead of Spain's Queralt Castellet.
In the men's event, Australia's Scotty James emerged victorious after a near-flawless second run helped him overcome Japan's Yuto Totsuka and Ruka Hirano.
James scored 97.80 on his second run to beat Totsuka by two points, while Hirano took the bronze.