[4] Ou started the 2018 season by competing at the Lingshui China Masters, and finished as the semi-finalist in the mixed doubles event partnered with Chen Lu.

Together with Feng Xueying, he won the mixed doubles title at the Syed Modi International, which is a Super 300 BWF tournament.

In the Indonesia Open, the duo beat Korea's Choi Sol-gyu and Kim Won-ho to become the first men’s doubles pair from the reserves’ list to win a Super 1000 title.

Compatriot and world no.1 Jia Yifan said after she won the deciding rubber, "We wouldn’t be here if not for the men’s doubles, they did a great job.

In the BWF World Tour, Ou and his partner Liu did not win a single title, their best achievement were a semi-finalist at the Indonesia Masters.