Under the dual pressures of a declining birth rate and rigid growth in childcare demand, private kindergartens face severe challenges of shrinking enrollment and urgent need for transformation. Integration of childcare and preschool education, as an internationally recognized model bridging the 0-6 early education and care system, offers a key solution to this structural contradiction. Based on the legislative context of the proposed Childcare Service Law and drawing on international experiences, this paper explores the legal foundations and institutional pathways for the transformation of private kindergartens toward integrated childcare and preschool education. It argues that legislation should affirm the legal status of private kindergartens in providing childcare services, establish a cross-departmental supervision mechanism led by education authorities with coordination from health departments, improve supporting standards such as the “dual certification integration,” and ensure systematic alignment with higher-level laws such as the Preschool Education Law. Through such institutional restructuring, the paper aims to safeguard the equal right to survival and development of private education and promote supply-side reform in childcare services.