The purpose of this study was to explore the process of self-concept transformation experienced by never-married single women in the expressive art therapy workshop. Based on intentional sampling, five women aged 20-30 who have never been married and have no partner were invited to participate in a two-day expressive art therapy workshop with a total of 6 units. The workshop was carried out in small groups, combining multiple activities such as music, writing, painting, labor, and games. The study adopted the method of hermeneutic phenomenology, and the data collection were activity reflection records, participant interview records, activity records, feedback records, participants’ art works, observation records. According to the data analysis, there were three research findings: First, the initial self-concept of ever-married single women is "waiting, confused, gradually recovering". Second, the group interaction and creative process, including the stage of immersion, the stage of interaction and co-creation, and the stage of openness and flexibility. Third, the transformation of self-concept from "loose and forward" in the early stage of the group, to "brave and pursuit", and finally to "uniqueness in the fusion relationship". Relevant recommendations are put forward based on the research results.