Refers to the family structure of four old people, a couple and a child. 42 1 family refers to the inverted pyramid family, that is, after a couple gives birth to a child, the child becomes the center of the family, and together with both parents, it forms a family structure with four elders and one child. This kind of family appeared in the process of carrying out the family planning policy in China, and later gradually became the main family structure in China society, which reflected the family concept and lifestyle of China people to some extent.