Lou Xuan was from Qi County (蘄縣), Pei Commandery (沛郡), which is around present-day Suzhou, Anhui.
After Sun Hao came to the throne in 264, he appointed Lou Xuan as a Central Regular Mounted Attendant (散騎中常侍) alongside Wang Fan, Guo Chuo (郭逴) and Wan Yu.
Lou Xuan later rose through the ranks and served as the Administrator (太守) of Kuaiji Commandery and then as Minister of Finance (大司農).
Sun Hao had secretly ordered Zhang Yi (張弈), a military officer stationed in Jiaozhi Commandery, to kill Lou Xuan.
However, Zhang Yi could not bear to kill Lou Xuan after seeing the latter's courageous behaviour in a battle against bandit forces.