After the "Lugou Bridge Incident", Peking University evacuated Beiping, Zhou Zuoren did not have a companion, chose to stay in the school, and reached a cultural cooperation with the Japanese, translating works for them, thus protecting the school property. In early 1939, Zhou Zuoren took over Wang Jingwei's appointment as the director of the National Peking University Library of the Nanjing Government and became the librarian of the university. In November 1940, Tang Erhe, superintendent of the General Administration of Education of the North China Political Affairs Committee of the Wang Jingwei regime, died of lung cancer, and the following month the Political Committee of the Central Committee of the Wang Jingwei regime decided to send Zhou Zuoren to take his place, and officially took office on New Year's Day in 1941. In October of the same year, Zhou Zuoren was appointed president of the East Asian Cultural Council, and later concurrently served as vice chairman of the North China Institute of Comprehensive Investigation and director of the China-Japan Cultural Association.
In December 1945, the Nationalist government arrested Zhou Zuoren in Beiping on charges of traitorous crimes and escorted him to Nanjing for trial in Laohuqiao Prison. His students and friends interceded for him one after another, and some even wrote a long letter to Hu Shi asking him to intercede for Zhou. In any case, the things that Zhou Zuoren had done could not escape the punishment of the law and the moral trial, and the 60-year-old was sentenced to 10 years in prison.
On the eve of the founding of New China, when political prisoners were released, Zhou Zuoren was also released and temporarily stayed in the homes of students in Shanghai. In August 1949, he returned to Beiping, which was already under the control of the People's Liberation Army. Afterwards, he wrote a letter of more than 1,600 words to the leaders, expressing his review and explanation of the past. After reading the letter, the leader said: "Zhou Zuoren is a cultural traitor, who has neither killed nor set fires. Now that there are not many people who know Greek, raise him up, do translation work, and publish it later. In this way, Zhou Zuoren began his life as a translator. Of course, he has a monthly salary to take, compared with the comfortable and comfortable life during the War of Resistance Against Japan, the current life is somewhat difficult. Especially after the death of his wife, Zhou Zuoren's life was even more difficult.
On May 6, 1967, when Zhou Zuoren went to the ground to relieve his hands, he suddenly fell ill and died, at the age of 82. After his death, the family informed Lu Xun's only son, Zhou Haiying, to come to his uncle's funeral. After thinking about it again and again, Zhou Haiying finally chose not to come to Zhou Zuoren's funeral, nor did she say a final farewell to her uncle. This also confirmed the words that Zhou Zuoren left behind when he first said goodbye to Lu Xun: Never see each other, and after breaking with Lu Xun, he and his brother's family completely broke off contact.