His most notable accomplishment was thwarting an attempted invasion by the influential Eastern Jin general Yu Liang in 339.
[3] In 312, Kui An and the others were sent to besiege the city of Yuanxiang (苑鄕, in present-day Hebei and Beijing) against You Lun (游綸) and Zhang Chai, who had surrendered to the Youzhou warlord Wang Jun.
He camped his generals Mao Bao and Fan Jun (樊俊) at Zhucheng (邾城, in modern Huanggang, Hubei), but this proved to be a fatal mistake.
Kui An brought the generals to invade the northern borders of Jingzhou and Yangzhou while sending 20,000 cavalry to attack Zhucheng.
In September, Shi Min defeated the armies south of the Mian River and killed their general Cai Huai (蔡懷).
Kui set his eyes on Shicheng but the Administrator of Jingling, Li Yang (李陽) mounted an impregnable defence and finally managed to put a stop to his advances.
Kui An lost 5,000 men against Li Yang, so he decided to retreat east of the Han River, sacking and pillaging the area while relocating 7,000 households to Youzhou and Jizhou.
[8] Kui An's attack proved devastating for Jin as their initial campaign to reclaim territory up north only resulted in losing land as well as people to Zhao.
[10] He served in Former Qin, and following its decline in 383, he along with a few others including Cui Hong fled to Jin, where they were given administrative posts of commanderies in Jizhou and led forces from south of the Yellow River.