As the basic structure of human society, family has long assumed the basic function of providing for the aged, and plays a decisive role in providing for the aged in rural areas of China. With the development and progress of social economy, especially the aging of population and the intensification of migration and mobility, the family structure in rural areas has undergone tremendous changes in scale, types and generations. The drastic changes in rural family structure in China will inevitably have an impact on family pension. Based on previous census data and sample data of population changes in recent years, this study analyzes the current situation, causes and trends of family structure changes in China, focusing on the impact of rural family structure changes on rural family pension in terms of economic support, life care and spiritual comfort, and finally draws research conclusions and puts forward relevant policy suggestions. This study is divided into five chapters. The first two chapters are the theoretical basis of this paper, the third and fourth chapters are the core chapters of this paper, and the fifth chapter is the conclusion of this paper. Chapter 1 is the introduction. This paper first expounds the background and significance of the topic, and then sorts out the relevant literature on family structure and family pension. On this basis, the research ideas and framework of this paper are put forward, and the data sources and research methods of this paper are expounded. The second chapter is the concept definition and theoretical basis. This paper defines the related concepts of family structure and family pension, and puts forward family life cycle theory, human capital investment theory, Maslow's hierarchy of needs theory and wealth flow theory to support this view, which makes theoretical preparations for the following research. The third chapter is the present situation, causes and trends of rural family structure changes. Based on the data of previous national censuses and the sample data of population changes in recent years, this chapter analyzes the new characteristics of rural families in China in terms of scale, structural types and intergenerational relations. It also systematically analyzes the reasons for the change of family structure from the perspectives of social economy, population flow, ideological concepts and policy changes. Combined with relevant research and forecast, the changing trend of family population in rural areas of China is given. The fourth chapter is the influence of rural family structure changes on family pension. This chapter mainly analyzes the positive and negative effects of changes in rural family structure on rural family pension from three aspects: economic support, life care and spiritual comfort. The analysis shows that the change of family structure has a dual impact on rural old-age care, both negative and positive. The fifth chapter is the research conclusion and policy suggestions. This chapter draws the conclusion that the influence of the change of family structure on family pension is unilateral rather than decisive, structural rather than functional, and the role of social pension on family pension is complementary rather than substitute. In terms of policy suggestions, this paper thinks that we should integrate Chinese and western concepts of providing for the aged and develop family culture of providing for the aged; Popularize the old age allowance and supplement the family pension resources; Develop domestic service industry to meet the nursing needs of the elderly; Encourage young adults to move to cities and towns with their parents.