Huyan Zan was born in Taiyuan, Bingzhou to the martial Huyan family. He started his military career at a young age as a cavalryman, and was soon promoted to a cavalry officer. In 964 Huyan Zan was instrumental in Song's campaign against Later Shu, leading his troops personally into battle. In 979 he once again showed his martial prowess in Song's campaign against Northern Han.
After the Song army launched several disastrous campaigns against the Qidan, Huyan Zan was appointed in 992 as governor of the border prefectures and was responsible for their defense. During his tenure (992-997) he reinvigorated the defense of the border region and held off numerous Qidan attacks. In 997 he resigned from his post after the death of Emperor Taizong and died in 1000.