In 1916, Zhu graduated from Secondary school and entered Peking University where he fell in love and married Wu Zhongqian. A year later, he changed his name from Zihua to Ziqing, the name change was said to be due to his family's dire economic conditions. Zhu graduated in 1920, and went to various secondary schools in Hangzhou, Yangzhou, Shanghai and Ningbo to teach. During his time as a teacher, he was also active in the poetry circles, and became a well-known poet.
Later, he was appointed professor of Chinese Literature at Tsinghua University in 1925, and on August 1928, he published his first essay collection known as "Retreating Figure". The book became a wild hit and he soon established his name as a prolific author and poet. However, it was also at this time when Zhu's wife died which was a terrible blow to him. From 1931 to 1932 he studied English Literature and Linguistics in London. He married his second wife Chen Zhuyin and continued to teach at Tsinghua University.
After the Second World War, Zhu encouraged his students in Kunming to oppose Chiang Kai-Shek from starting the Chinese Civil War. In 1946, he returned to Beijing and was appointed the Head of the Chinese Language Department in Tsinghua University. When he heard of the assassination of patriotic authors Li Gongpu and Wen Yiduo, Zhu disregarded his own safety to attend the funeral of both men.
Zhu later died in 1948 after joining the rebellion of refusing aid from the United States. Most people believe that Zhu died of starvation due to the Mao's famous article "Farewell, Leighton Stuart". However, The real cause of Zhu's death was gastric perforation result from his severe stomach ulcers.