1. Form innovation and ideological content: Sunrise is a four-act film after Thunderstorm, which is quite different from Thunderstorm in subject matter and form, reflecting the playwright's exploration spirit and outstanding talent. Cao Yu thinks that Thunderstorm is "too theatrical" and "overused" in techniques, and decides to abandon the structure used in Thunderstorm and adopt the structure in Sunrise.
The "cross-sectional description" is used to change the previous highly compressed and compact structural model, and the "fragment method" is used to show the life features of different characters, so that the audience can have an overall impression of the social life at that time. Sunrise is set in a gorgeous lounge of a hotel. Chen Bailu, a social butterfly, heard and witnessed all kinds of ugly phenomena in the metropolis at that time, and integrated many people and events from all walks of life into a special model, reflecting the bloody world in that bizarre social reality. There are not only the oppression and bullying of the working people by bureaucrats and comprador capitalists, but also the extravagance, corruption and intrigue within the bourgeoisie. At the same time, it is also full of scenes in which a group of small people struggle for survival.
2. The double symbolic meaning of "sunrise": In Cao Yu's view, "sunrise" symbolizes the "heaven" with more damage.
That is, the author's ideal bright society. Deeply disappointed with society and life, Chen Bailu chose to die before sunrise, leaving the sun behind, which became an unattainable pursuit. Her death is undoubtedly a silent resistance and accusation against that decadent and dark society. In Cao Yu's subconscious, "sunrise" has another meaning, which is the desire for happy love and ideal home. Under the surface structure of Sunrise, there is a story about home. In the process of interacting with different men, Chen Bailu looks for a home to rely on, but she can only stay in the hotel all the time, leaving this world with longing for home, deep despair and disappointment of not seeing the sunrise. It is this hidden line unconsciously set from the deep heart that makes Sunrise more meaningful and intriguing, instead of becoming a simple world cartoon.