The ongoing stability of supply chains faces significant challenges from trade protectionism, anti-globalization trends, and the COVID-19 pandemic. To remain resilient in this dynamic market environment, supply chains must evolve through iterative upgrades and transition to a higher level of sustainability, a process termed “step development.” The current literature, however, offers limited insights into achieving such step development in supply chain sustainability and its critical supporting elements. This study, grounded in theory, involved interviews with representatives from eight diverse Chinese enterprises. We introduce a model delineating supporting factors and a roadmap for Sustainable Step Development of Supply Chains (SSDSC). Our findings highlight three pivotal categories of support for SSDSC: institutional, technological, and social factors. Additionally, we observed that external influences in these categories positively modulate their internal counterparts. The study identifies industrial technology, digital intelligence technology, corporate responsibility, and stakeholder needs as key elements in this process. We conclude by offering theoretical and practical recommendations to foster SSDSC.