After the establishment of the People's Republic of China, Lü was a professor in the Chinese Department of Tsinghua University from 1950 to 1952.

He was a committee member and vice director of the important China Language Reform Commission.

He was editor-in-chief of the authoritative Xiandai Hanyu Cidian, and served on the editorial board for the Encyclopedia of China.

In 1987, he was awarded honorary Doctor of Literature by the Chinese University of Hong Kong.

In addition, he was the father in law to Chinese physicist Tang Xiaowei and uncle to Peking University educated scholar Lü Qisu.