Early career Wu 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. Wu'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. Wu's next fight was a rematch against Bo Meng at CKF 7/7, which Wu 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 Wu 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, Wu 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 Wu faced the debuting Zuriana Makoeva, stopping her through a TKO in the fourth minute of the second round.
Ultimate Fighting Championship Wu made her UFC debut on November 25, 2017, at
UFC Fight Night 122 against
Gina Mazany. She lost the fight via unanimous decision. Wu faced
Lauren Mueller on November 24, 2018, at
UFC Fight Night 141. She won the fight via first round armbar. Wu was scheduled to fight
Luana Carolina on May 11, 2019, at
UFC 237, but was forced to pull out due to an injury. The fight was rescheduled for
UFC Fight Night 157 on August 31, 2019, however Carolina pulled out of the fight due to a fractured spine. Wu instead faced former DEEP Jewels champion
Mizuki Inoue. At the weigh-ins, Wu weighed in at 129 pounds, three pounds over the flyweight non-title fight limit, and forfeited 30% of her purse to Inoue. Wu lost the fight via split decision. Wu was scheduled to face
Bethe Correia on December 5, 2020, at
UFC on ESPN 19 However, due to
visa issues, they were rescheduled for
UFC on ABC 1 on January 16, 2021. In early January 2021, it was reported that Corria was forced to withdraw from the bout due to undergoing surgery to remove her
appendix. On January 7, it was announced that Wu would face UFC newcomer
Joselyne Edwards. She lost the fight via unanimous decision. Wu was scheduled to face
Nicco Montaño on July 31, 2021, at
UFC on ESPN 28. However, the fight was canceled after Montaño missed weight by seven pounds at the weigh-ins. Wu was scheduled to face Josiane Nunes on February 26, 2022, at
UFC Fight Night 202. However, Wu was pulled from the bout for undisclosed reasons and was replaced by promotional newcomer Jennifer Gonzalez. Wu faced
Mayra Bueno Silva on April 16, 2022, at
UFC on ESPN 34. She lost the fight via unanimous decision. This fight earned her the
Fight of the Night award. Wu faced returning veteran
Lucie Pudilová on August 20, 2022, at
UFC 278. She lost the bout via TKO stoppage in the second round due to elbows on the ground. In August 2022, it was announced that Wu was no longer on the UFC roster.
Post UFC In her first bout after leaving the UFC, Wu faced
Wang Cong on January 20, 2024 at Kunlun Fight 95, losing the bout via unanimous decision. ==Championships and accomplishments==