It is not known when or where Zheng Jue was born. He was a grandnephew to the Tang Dynasty official Zheng Qi, who served as a chancellor during the reign of Emperor Zhaozong of Tang. Zheng Jue's father Zheng Hui served as an assistant to the late-Tang warlord Zhang Quanyi, who served as the mayor of and controlled the Tang eastern capital Luoyang during those years. Zheng Jue passed the imperial examinations in the Jinshi class during Emperor Zhaozong's Guanghua era. For the rest of Tang Dynasty, he served successively as a copyeditor at Hongwen Pavilion, an assistant at Jixian Institute, and an imperial censor with the titleJiancha Yushi.
During Later Liang
After Tang fell and was succeeded by Later Liang, Zheng Jue served initially as a Bujue, then an imperial chronicler, then an imperial scholar, then the deputy minister of rites. It was said that throughout Zheng's career, Zhang Quanyi exerted his influence to aid Zheng in his promotions. Zheng was also known for writing beautifully and elegantly. In 916, during the reign of Later Liang's third and final emperor Zhu Zhen, Zheng Jue was made Zhongshu Shilang and given the designation Tong Zhongshu Menxia Pingzhangshi, making him a chancellor. In 923, as the Later Liang capital Daliang was left defenseless as Later Liang prepared a massive four-prong attack against its rival north of the Yellow River, Later Tang, Later Tang's emperor Li Cunxu launched a surprise attack on Daliang itself. When Zhu realized it and summoned his officials for a last-ditch strategy session, Zheng suggested that Zhu give him the imperial seal and let him head toward the Later Tang camp, claiming to be surrendering, to see if that would slow the Later Tang advance. Zhu himself was skeptical as to whether this would work, and Zheng then admitted that there was no likelihood for success, drawing laughter from others. With Li Cunxu's army approaching Daliang, Zhu committed suicide, ending Later Liang.
During Later Tang
After Later Tang's conquest of Later Liang, Li Cunxu, who saw himself as the legitimate successor to Tang, exiled a number of Later Liang officials who were from Tang aristocratic families, to punish them for, he reasoned, betraying Tang. As part of these exiles, Zheng Jue was sent to Lai Prefecture to serve as its census officer. Shortly thereafter, he was slightly promoted to be the military advisor to the prefect of Cao Prefecture. Nevertheless, Zhang Quanyi, who had become an honored Later Tang official after submitting to Later Tang, was interceding for him with Li's chief of staffGuo Chongtao, trying to get him made chancellor again; instead, though, he was made an advisor to the Crown Prince — an honorary position as there was no crown prince at that time. In 926, Li Cunxu was killed in a mutiny at then-capital Luoyang. His adoptive brother Li Siyuan, who had previously rebelled against him, arrived at Luoyang shortly after and became emperor. Shortly after, the general Ren Huan returned from a campaign against Former Shu, and was expected to be made chancellor. Li Siyuan's chief of staff An Chonghui, not wanting Ren to serve as chancellor alone, sought to have someone else serve with Ren. An's close associate Kong Xun recommended Zheng, claiming that during Zheng's service as Later Liang chancellor, he was cautious and lenient, capable of writing, and capable of judging character. An thus recommended Zheng to Li Siyuan. Subsequent, Li Siyuan made Ren and Zheng chancellors. Meanwhile, as shortly after two other chancellors that Li Cunxu had commissioned, Doulu Ge and Wei Shuo, were removed from their offices, there were talks of more chancellor commissions. Kong recommended Cui Xie to An, while Ren recommended Li Qi. However, both Zheng and Kong disliked Li Qi, which led to disputes between them and Ren. Eventually, Li Siyuan commissioned Cui and Feng Dao as chancellors. In 928, Zheng, who was then, in addition to being chancellor, also serving as Menxia Shilang and minister of justice, requested retirement. Li Siyuan gave him the title of Zuo Pushe and allowed him to retire. Li Siyuan also gave him the honorary title of Kaifu Yitong Sansi and granted him an estate at Zheng Prefecture. He died early in Li Siyuan's Changxing era and was given posthumous honors.
