2009 she finished her weightlifting grand slam by taking gold in Chinese National Games with a result of 125 kg in the snatch, 150 kg in the clean and jerk adding to 275 kg total. In the 2009 weightlifting world championships she wasn't able to sustain her supremacy over the 75 kilo weight class as Svetlana Podobedova of Kazakhstan swept three gold medals, Cao following her to take silvers in all three disciplines. Later that year she represented her country in East Asian Games taking gold with routine performance of 252 kg total.