Against the background of slowing global growth, intensifying geopolitical conflicts, and a profound restructuring of international economic and trade rules, the transformation of China’s foreign trade has become a major issue in advancing high-standard opening up and building China into a strong trading nation. From the institutional logic of promoting reform through opening up, this paper reviews the historical achievements and stage transition of China’s foreign trade, systematically examines the multiple drivers of its transformation as well as the major constraints it faces, and then proposes corresponding breakthrough paths. The study finds that China’s foreign trade transformation is jointly driven by three forces: endogenous drivers arising from shifts in dynamic comparative advantage, exogenous drivers associated with intensifying major-power competition, and the growing domestic demand for high-quality institutional supply. At the same time, the transformation process remains constrained by the insufficient conversion of potential advantages into actual competitiveness, weak control over high value-added segments of global value chains, rising major-power rivalry and international uncertainty, and inadequate institutional supply under deeper opening up. On this basis, the paper proposes a set of policy paths for advancing foreign trade transformation, including steadily expanding institutional opening up, optimizing market diversification and supply-chain networks, upgrading trade patterns while expanding high-quality imports, developing services trade and digital trade, strengthening indigenous innovation, and actively participating in global economic governance. These efforts will help accelerate the shift of China’s foreign trade from a scale-expansion orientation to a quality-and-efficiency orientation, thereby facilitating the transition from a major trading nation to a strong trading nation.