He probably hailed from the state of Zhao 趙, where he was a minister of King Wuling 趙武靈王 (r. 326-299) and recommended to use tactical styles of the riding tribes of the north in order to fight them. This tactic included not only mounted archery (qishe 騎射), but also the use of "barbarian" short jackets (hufu 胡服). Lou also urged King Wuling to conclude alliances (meng 盟) with the states of Qin and Chu 楚.
After King Wuling's passing away, Lou Huan went to Qin, where he served King Zhao 秦昭襄王 (r. 307-251) for twelve years, and then decided to retire. After the battle of Changping 長平 (close to modern Gaoping 高平, Shanxi) in 259, in which Qin nearly annihilated the forces of Zhao, Lou visited the court of King Xiaocheng of Zhao 趙孝成王 (r. 266-245) and suggested that Zhao might become a vassal of Qin. Yet King Xiaocheng was urged by some of his ministers – mainly Yu Qing 虞卿 and Lord Pingyuan 平原君 – not to do so.