After the September 18th incident, he came under the influence of the Communist Cao Manzhi (曹漫之), and began to read Marxist books.

In 1933, Li was transferred to the Education Museum as an administrator, at the same time, he worked as a member of the underground Party and gathered top secret information for the CCP Jiaodong County Committee.

In 1934, Li Yaowen and Cao Manzhi used the Education Museum as a base for they propagating patriotism and communism.

In November, he participated in the Huaihai Campaign led by Liu Bocheng, Su Yu, Chen Yi and Deng Xiaoping in north China.

He served as Jinan Military Region director until 1968, when he was succeeded by Chen Jide (zh:陈继德).

[5] On September 13, 1971, Lin Biao tried to flee the Soviet Union but he suffered an air crash and died in Ondorhaan, Mongolia.

After receiving the valuable information provided by the Chinese Embassy in Mongolia, Li proved Lin's death.

On March 14, 1988, the Vietnam People's Navy invaded the Johnson South Reef, and killed some Chinese soldiers.

Li retired in July 1998, and that same year, the Chinese government bestowed its Red Star medal, 1st Class upon him.