In elementary and middle schools in China, core subject teachers serve as homeroom teachers in most classes. Nevertheless, some schools are beginning to try to use non-core subject teachers as homeroom teachers. A series of disputes have arisen over the non-core subject teacher serving as the homeroom teacher. Based on defining the concepts of the core subject, non-core subject, and homeroom teacher, this paper summarized the two viewpoints of whether core and non-core subject teachers can become homeroom teachers; and then discussed the role and the potential reasons of the non-core subject teacher as the homeroom teacher for being blocked, and some solutions are proposed. It is hoped to inject new vitality into the position of homeroom teacher by discussing this phenomenon.