Education in the new era advocates taking students as the main body and improving students’ core literacy on this basis. Subjectivity has also become one of the keys to quality education. Primary school is not only the initial stage of life, but also the key period to develop students’ subjectivity. At present, there are many problems in class activities, such as the weak concept of taking students as the main body, the lack of subject consciousness among students, the flawed construction system of class activities, the unreasonable evaluation system of class activities, and so on. By establishing the role-playing model under the background of “class activity month,” students can play different roles in class activities and participate in various links, such as theme selection, scheme design, organization, implementation, summary, and evaluation of class activities. Through this process, it does not only improve the quality of class activities, but also cultivate students’ subject consciousness and ability in a certain subject, thus highlighting their subject status in class activities.