In the period of social transformation, the family is undoubtedly one of the rapidly changing fields. Chizuko Ueno, a Japanese sociologist, introduced the concept of family self-identity to analyze the family situation in Japan's transition period and describe the differences between consciousness and reality and family members. She believes that "home" has always been regarded as an entity beyond the individual, but if family members lose their sense of "home", "home" will collapse.

Some problems of left-behind wives and children caused by the long-standing phenomenon of single people working in the east of Japanese society are similar to those of left-behind children caused by large-scale population movement in China. Therefore, Japan's research on single employment and the theory of family sociology can also provide reference for the study of left-behind children in China. Because the phenomenon of single working in Japan is very similar to the large-scale migration of population in China, especially the migration of migrant workers, the family self-identity theory applicable to the study of family changes in Japan's social transition period is also applicable to the study of left-behind children in China.

In fact, as Professor Fei Xiaotong, a famous sociologist in China, said in the first "Pan Guangdan Memorial Lecture" of the Chinese University of Hong Kong on September 25th 1992, in the past, our research on farmers in China was mainly confined to the humanistic and ecological level, ignoring the social mentality level. Judging from the current research situation of left-behind children in China, some existing research results also ignore the research on the social mentality of left-behind children and their families. In fact, how do left-behind children feel in their daily lives, in the community, at school, and in the families left behind or fostered? What is the meaning of family to left-behind children? From the morphological point of view, the family life of left-behind children is either lack of one parent or both parents. So what is the left-behind children's understanding of "home" in a "single-parent family" without one parent or a foster family without two parents? What are the needs and expectations for "home"? How do they interact with others in family life, community life and school life? How does this life affect your own development? This kind of problem can be explained by family self-identity theory. The author borrows the theory of family self-identity consciousness put forward by Japanese sociologist Chizuko Ueno as a new perspective to study the problem of left-behind children, and hopes that academic colleagues can explore the social mentality of left-behind children and left-behind families from such a research perspective and open up a broader academic space in the study of left-behind children.