Luo Tian-yi, a native of Songcheng, Zhending Road (now Songcheng County, Hebei) during the Yuan Dynasty. He was educated by his father from a young age and aspired to study the classics and history. In the later years of Li Gao (after 1244), he studied medicine under Li for several years, mastering his techniques. After Li Gao's death, Luo compiled and published several medical works by Li Gao, playing a significant role in spreading the "Dongyuan School."

After 1251, he returned to his hometown to practice medicine, gaining fame for his skill in treating sores, and became a royal physician. When the Yuan army moved south, Luo Tian-yi repeatedly followed the army on campaigns. While in the military, he also sought out teachers and sages to improve his medical skills. In his later years, aside from his medical practice, he based his work on the theories of Neijing and the teachings of Jiegu and Dongyuan, extensively incorporating various schools of thought and combining them with his own insights. In 1281, he wrote the Weisheng Baojian in twenty-four volumes.

Luo Tian-yi lived during the late Jin and early Yuan periods. His academic thoughts were remotely inherited from Jiegu and directly taught by Dongyuan. He emphasized the "Yishui School" characteristics of zang-fu organ differentiation, spleen-stomach theory, and the application of medicinal properties, becoming a pivotal figure in the formation and development of the Yishui School's theoretical framework.

Luo's main academic thoughts are reflected in the Weisheng Baojian. Luo also authored works such as Neijing Leibian, Yaoxiang Tu, Jingyan Fang, and Yijing Bianhuo (seen in Liu YinJingxiu Wenji), all of which are now lost. The compiled works of Zhang Yuan-su include Jiegu's Commentary on Nan Jing.