First, Yu Chaoen took advantage of the Anshi Rebellion. After the Anshi Rebellion, the political situation was turbulent, so Yu Chaoen seized this opportunity and climbed to the position of the leader of the Shence Army to defend the Tang King. After Yu Chaoen got this hard-won official position, he became the first eunuch in the Tang Dynasty. In the ancient imperial palace, the position of eunuch leader was also very high, so Yu Chaoen was a little lawless at this time, which even seriously affected several circles in the Tang Dynasty. However, Yu Chaoen was a eunuch trusted by the emperor, so many officials left it alone.
Second, Yu Chaoen framed Guo Ziyi. After Yu Chaoen ascended the position of the first eunuch, he was also called the commander-in-chief of the body guard, so it was also the realization of his rights. On the other hand, Guo Ziyi thought he was a very capable general, so the Tang King wanted to promote Guo Ziyi. Guo Ziyi's promotion is bound to affect Yu Chaoen's influence, so Yu Chaoen framed Guo Ziyi many times. In 758, Yu Chaoen besieged An Qingxu, but the war failed, and Yu Chaoen put the blame on Guo Ziyi.
Third, Yu Chaoen dug Guo Ziyi's ancestral grave. Yu Chaoen, who has been framing Guo Ziyi, is not satisfied with his current state. During the Tang Daizong period, Guo Ziyi was ordered to enter Korea. Yu Chaoen felt that Guo Ziyi hindered his career, so he used his power to dig Guo Ziyi's ancestral grave.