"The scientific literacy of teenagers is the foundation for creating an innovative country and a comprehensive well-off society. Although many studies in recent years have explored the influencing factors on adolescents' scientific literacy, few have included the influence dimension of both schools and families, and further tested the cross-level interactions between the two. Therefore, this paper emerged from the theory of the ecological systems of human development proposed by Bronfenbrelmer to test the influence of parental emotional support (family dimension) and school autonomy (school dimension) on students' scientific literacy. Using the multi- level analysis to investigate three main questions: (1) What is the effect of parental emotional support on the scientific literacy of students? (2) Does the school autonomy have a significant impact on students' scientific literacy? (3) Does the school autonomy regulate the influence of parental emotional support on students' scientific literacy. This study used the empirical data released by PISA 2015 data of Beijing, Shanghai, Guangdong and Jiangsu Provinces, the valid number of students was 7667, from 257 schools. The results were: (1) Parental emotional support does have a significant positive impact on students' scientific literacy; (2) The index of the school autonomy relating to curriculum and assessment have a significant negative impact on students' scientific literacy; (3) There is a significant cross-level interaction between parental emotional support and the index of the school autonomy of school staff in allocating resources. Specifically, the latter will weaken the positive impact of the former on the scientific literacy of students."