The focus of Prison Green is to vividly depict the green branch and the moral of this article from different angles. I represent the people of China oppressed by Japanese imperialism. "I" love green shows that the oppressed people do not give in in the dark and pursue light. Because "green" is a symbol of life, happiness and happiness, which can comfort the author's mind. The central idea is to describe its characteristics, express the author's love for ivy, expose the darkness of society and people's misfortune after the Lugouqiao incident, and praise the noble character of never giving in in the dark.