Family education is one of the most enduring forms of education that mankind has ever known. The function and status of family education in China has developed along with the development of the new era. The legislation on family education is an important milestone for family education in China, and the implementation of the “double reduction policy” has promoted the new development of family education. As a topic of family education research, parental Cooperative education has important theoretical and practical significance. In this paper, the data of parental pairs were selected from the National Youth Mental Health Database of the Institute of Psychology of the Chinese Academy of Sciences for analysis. The results showed that parental consistency was significantly and positively related to parental relationship quality; parental depressive mood state was significantly and negatively related to parental relationship quality; and parental consistency had a greater impact on parental relationship quality when the parents were in an unstable situation. Based on the study of the relationship between parental consistency, parental psychological state, and parental relationship quality, it is of positive significance to further explore parental cooperative education and to explore the process of cooperative parenting and the need for parents to maintain a consistent philosophy of cooperation, a state of cooperation, and a cooperative relationship in accompanying their children can have positive implications for the development of family education in China.