The expansion of China’s cross-border e-commerce (CBEC) and international trade has catalyzed the establishment of overseas warehouses, particularly in response to the increasing trade volume with countries involved in the Belt and Road Initiative (BRI). This study develops a decision-support framework to assist CBEC businesses in selecting the most appropriate third-party logistics (3PL) providers for the sustainable operation of overseas warehouses. Through a comprehensive review of existing literature and expert validation, the selection criteria are categorized into seven primary groups. The first four criteria – location and infrastructure, technology and information systems, operations and service quality, and international trade regulations – are integral to evaluating 3PL providers, particularly in the context of international logistics and supply chain networks. The additional three criteria emphasize sustainability, addressing economic, environmental, and social dimensions, which are essential for assessing 3PL providers in the of sustainable overseas warehouses operations for CBEC. In total, 24 sub-criteria are established to facilitate the evaluation process. A hierarchical decision-support framework is developed, employing a multi-criteria decision-making (MCDM) approach to systematically assess and select optimal 3PL provider, ultimately enhancing the operational efficacy of overseas warehouses in the CBEC sector.