Wu Yanan made her pro debut in 2013 under the banner of Fighting China, facing fellow debutante Joo Young Lee. Yanan won the bout by a first round TKO. Yanan's first appearance with the Chinese Kung Fu Championships came almost a year after her first fight, at CKF 9/21. She faced Bo Meng who was coming off of a win against Zhang Weili. Yanan won the fight by a unanimous decision. Six months later she faced Yang Liu, who was making her pro debut. Yanan won through a first round TKO. Yanan's next fight was a rematch against Bo Meng at CKF 7/7, which Yanan won by a split decision. At CKF 4: Day 1 Yanan faced another debutante in Jinghuan Zhu, which she won by a first round submission. It was her first and only fight at featherweight At WLF E.P.I.C. 5 Yanan fought against Bayarmaa Munkhgerel, who hadn't yet won a pro fight, and won through a second round TKO. She returned to CKF to face Saeedeh Fardsanei who was making her debut, and won by a first round TKO. Leaving the Chinese Kung Fu Championships, Yanan fought against the 8-2 Yana Kunitskaya under the banner of Fightspirit Championship at Fightspirit Championship 6. She suffered the first professional loss of her career, with Kunitskaya stopping her by way of TKO, after only 32 seconds of the second round. Fighting at Kunlun Fight MMA 7, Yanan faced the 0-3 Anjela Pink winning in the first round through a TKO. At WLF W.A.R.S. 12 Yanan faced the debuting Zuriana Makoeva, stopping her through a TKO in the fourth minute of the second round.
Wu Yanan was scheduled to have her first fight in the UFC on 25 November 2017, at UFC Fight Night 122 against Gina Mazany. Yanan lost a unanimous decision. Her next fight was scheduled for UFC Fight Night 141, in her home country of China, against Lauren Mueller. Mueller would dominate on the feet, but Yanan would end up winning by a first round armbar. Mueller fought on five weeks notice as replacement for Shana Dobson who was injured in training as was unable to fight. Yanan was scheduled to fight Luana Carolina at UFC 237, but the Yanan was forced to pull out due to an injury. The fight was again made and scheduled for UFC Fight Night 157, but this time the Brazilian flyweight pulled out due to a fractured spine. Carolina was replaced by the former DEEP Jewels champion Mizuki Inoue. Yanan missed weight and would forfeit 30% of her purse. In a fight contested entirely on the feet, Yanan lost by way of a split decision.
