The school social work service contents and level makes certain progress but faces many predicaments and obstacles and its core capacity must be improved. The research finds that the core capacity of school social workers is expressed in such nine aspects as respecting the diversification of the students, self reflection and growth, flexibly sticking and waiting, interculture and interdiscipline, policy analysis and advocating, item design and management, establishment and maintaining relation, dynamic system evaluation, and team coordination and integration. The cultivation of school social worker core capacity should consolidate the guidance and support of national and the Party’s policies and guideline in macrolevel. In middlelevel, the core capacity of school social workers can be improved by specialized education and on duty training. In microlevel, school social workers should learn a lot, self examine, carefully think, clearly distinguish the wrong and the correct, and practice.