He hailed from Yingchuan 潁川 (modern Xuchang 許昌, Henan). Li Ying excelled in the selection of state appointees and rose the ladder of career up to the post of regional inspector (cishi 刺史) of the province of Qingzhou 青州. He was known for his severe style of administration, and when it became known that he was appointed, all officials left their post.
Li Ying left soon his post for private reasons and retired to Lunshi 綸氏 (modern Dengfeng 登封, Henan), where he engaged in teaching.
In 156 CE he was appointed general and suppressed a rebellion of the Qiang 羌 tribes in the west. For his success, he was promoted to metropolitan commandant (sili xiaowei 司隸校尉).
At that time rampant corruption was seen among the powerful eunuch clique at the capital. Li Ying decided to fight against the ever-growing dominance of the eunuchs at the court. He looked for allies among the higher officials and found them in Guo Tai 郭泰 and Chen Fan 陳蕃. Yet in 166 he was slandered by the eunuchs and put into prison. When he was released he was forbidden to resume any office during lifetime.
With the accession of Emperor Ling 漢靈帝 (r. 167-189), his faction found high support in the person of general Dou Wu 竇武, brother of the Empress Dowager. Li Ying was appointed Chamberlain for the Palace Revenues (shaofu 少府) of the Changle palace 長樂. Secretly, the men planned to execute the whole eunuch faction, but the plan was reveiled, and Li Ying was incarcerated and killed.