Excellence and equality is an essential goal of compulsory education in China. This goal, however, is difficult to achieve in practice because of the difficulties in balancing between excellence and equality and in sustaining equality as a result of resource redistribution. This article uses the data of the nationally representative China Education Panel Survey (CEPS) and discusses the possibility of advancing educational excellence and equality in compulsory education based on Coleman's theory of social closure. To be more specific, social capital can be increased by means of school-family cooperation so as to achieve excellence and equality in compulsory education. Our main findings include: first, school-family cooperation system is conducive to the growth of social capital for families; second, it adjusts the direct influence of family background on the social closure production; third, it helps achieve excellent development of compulsory education by increasing family social capital; finally, the school-family cooperation system facilitates even distribution of social capital among different classes and equal development of compulsory education. On such a basis, this paper further discusses the policy implications of these findings.