During the An Shi Rebellion, he surrendered to An Lushan and served as chancellor of An's state of Yan at Luoyang.
It is not known when Chen Xilie was born, but it is known that he was from Sòng Prefecture (宋州, roughly modern Shangqiu, Henan).
Later, he was made Zuǒ Xiàng (左相), the head of the examination bureau and a post considered one for a chancellor, as well as the minister of defense (兵部尚書, Bīngbù Shàngshū).
When Li Linfu's close associate Wáng Hóng (王鉷) was implicated in a rebellion plot contrived by his brother Wáng Hàn (王銲), Li Linfu tried to extricate him, but Chen and Yang insisted that Wang Hong was guilty and should be further investigated, eventually leading to Wang Hong's being forced to commit suicide.
In 754, Emperor Xuanzong made Chen a senior advisor to his son Li Heng the Crown Prince and removed him from his chancellor position, replacing him with Wei Jiansu.
Some 300 former Tang officials who had accepted Yan offices, including Chen, changed into mourning clothes and begged for forgiveness.
After they formally paid respect to Emperor Suzong and apologized, they were delivered to the supreme court and placed under arrest.
They were tried jointly by the officials Lǐ Xiàn, Lǚ Yīn, and Cuī Qì (崔器).