The family unit is foundational to a child's cognitive and social development. Variations in family dynamics significantly influence disparities in educational outcomes. This study aimed to explore the effects of family socio-economic variables on students' learning behavior at home and learning engagement at school. It examined the effects of family income, the father and mother's education level or cultural capital, and their communication with teachers on students learning engagement at school through the mediation role of students' learning behavior at home. The sample in an online survey was 2476 parents and teachers across China, and data was analyzed using SPSS, PROCESS macro for SPSS, and JASP. The findings highlight the importance of parent-teacher communication, which exhibited a significant total effect on student engagement. This influence surpasses other factors, such as family income and the education level of mothers and fathers, on students' learning engagement at school. Thus, the study emphasizes effective communication between parents and teachers in fostering students' learning engagement.