The actor Zhang Hanyu, who played Gu Zidi, got the role with twists and turns. Originally Zhang Hanyu took the script and went to the director Xiaogang Feng and asked Ying to play Gu Zidi, but the director laughed at that time and said that it was performed by Ge You . He went home and read the script many times. Later, the director decided to let him play Zhao Erdou. Initially, "Assembly" selected many actors to try Guzidi's role. Zhang Hanyu has always played with them in the role of Zhao Erdou, and the director has never let him audition for Guzidi. Zhang Hanyu can also understand the director's thoughts. Xiaogang Feng feels that Zhang Hanyu has a stronger atmosphere of a Beijing courtyard student, which is completely different from a character like Gu Zidi. However, in August 2006, the director and investors finally decided that Zhang Hanyu should play Gu Zidi
.
When director Xiaogang Feng first found Chao Deng to try out three roles-Gu Zidi, Zhao Erdou and Wang Jincun. It was Zhang Hanyu who cooperated with him during the audition. However, due to scheduling issues, Chao Deng first went to work on the film crew of "Sweet Honey". During the filming process, director Xiaogang Feng got in touch with him again, hoping that he could play the role of Zhao Erdou. Xiaogang Feng also specially coordinated with the director Gao Xixi of "Sweet Honey" for the schedule of Chao Deng
.
The determination of the heroine of "Assembly" also experienced a lot of twists and turns. After Chen Shu quit the filming, the director finally determined that the role of Sun Guiqin was the newcomer Tang Yan at the time. During the audition process, Tang Yan couldn't help crying when she talked about some of her family's experiences. Her unmodified narration showed no trace of performance. Xiaogang Feng's simple and sincere performance made Xiaogang Feng also shed tears
. Liao Fan was originally set to star in Liu Zeshui, who was later changed to the role of Jiao Dapeng due to his age
.
