The jurisprudential basis for legislating the Private Economy Promotion Law lies in constitutional protection principles and business freedom principles, with the law serving functions of protection, promotion, regulation, and guidance. Based on reference to relevant legislative experiences such as the U.S. Small Business Act system, German SME promotion legal norms, and the evolution and institutional innovation of Japan’s Basic Law for Small and Medium-sized Enterprises, this paper comparatively analyzes the common characteristics and differences of typical foreign legislative models, revealing their implications and limitations for Chinese legislation. From an internal perspective, theoretical reconstruction and improvement should be made based on the Private Economy Law (Draft for Comments) in terms of political guarantees, core concepts, basic principles and specific provisions, the connotation and extension of core concepts, and other core systems. Meanwhile, from an external perspective, systematic coherence construction of the Private Economy Promotion Law should be carried out to form connection and conflict resolution mechanisms with the existing legal system and to build a multi-subject law enforcement supervision system. In the field of rule of law, the “ought to be” of the Private Economy Promotion Law should be clarified to examine the “is” of the “Draft for Comments”, thereby providing some theoretical thinking, review, and judgment for the ongoing legislation.