Li Delin was said to be highly intelligent from his childhood, and even before he turned 10 he was able to quickly memorize and recite the lengthy poem Shudu Fu (蜀都賦) by Zuo Si (左思), impressing the high-level official Gao Longzhi (高隆之).
Sometime before 557, Gao Jie (高湝) the Prince of Rencheng, the governor of Ding Province (定州, roughly modern Baoding, Hebei) and brother to Emperor Wenxuan of the newly established Northern Qi (Eastern Wei's successor state), impressed with Li Delin's talent, invited Li to his mansion and treated him as a friend, not as a subordinate.
In 573, when Emperor Wucheng's son and successor Gao Wei, who had a love for literature, established Wenlin Hall (文林館) to retain officials with literary talent, he made Li and Yan Zitui (顏子推) co-directors.
It was at Li's suggestion that Yang immediately made his intentions to eventually take the throne known by assuming particularly elevated titles while serving as regent.
Emperor Wen subsequently did slaughter members of the Yuwen clan, and after this incident, he never again promoted Li—and it did not help that Li, who was proud of his own abilities, generally had poor relations with other high-level officials.
In winter 587, when Emperor Wen visited Tong Province (同州, roughly Weinan, Shaanxi), Li initially did not follow him on account of illness.
Second, when Yu, after realizing the problems created by township mayors, suggested that the mayoral posts be abolished, Li, while initially opposing the proposal, opposed its abolition, reasoning that laws should not be changed so quickly using language that caused Emperor Wen to believe that Li was comparing him to Wang Mang.
Emperor Wen, citing these issues, removed Li from his post and made him the governor of Hu Province (湖州, roughly modern Huzhou, Zhejiang).
Li was later moved to Huai Province (懷州, roughly modern Jiaozuo, Henan) and died as its governor, at age 60, probably in 591.