At present, the study of public administration embodies the integration of social science disciplines. The main purpose of this study is to explore interdisciplinary research in public management by analyzing the theory and practices of economics and sociology. A qualitative method has been employed to obtain the objectives. This study reveals that the diversification of public administration research is a manifestation of the diversity, complexity and comprehensive development in the field of public management. Economics and sociology provide new perspectives and research methods for public administration in different aspects. With the change of the value orientation of national development, the research of public management should also be re-examined.