Driven by the carbon peaking and carbon neutrality goals and against the backdrop of the vigorous development of the global green building industry, the demand for cross-border procurement of environmentally friendly building materials, the core carrier of green buildings, has been on a steady rise. The cross-border procurement supply chain for environmentally friendly building materials involves multiple subjects, links and scenarios, and poor collaboration has become a key bottleneck restricting the efficient supply, cost control and realization of green value of environmentally friendly building materials. Based on the development demands of green buildings, this paper systematically analyzes the current collaboration status of China’s cross-border procurement supply chain for environmentally friendly building materials, and dissects the prominent problems and their root causes such as insufficient subject collaboration, information asymmetry, low logistics efficiency and disunified standards. Combining the supply chain collaboration theory and green management theory, it constructs a five-in-one collaboration mode of “subject collaboration-information collaboration-logistics collaboration-standard collaboration-benefit collaboration”, clarifies the core content, operation mechanism of each collaboration dimension as well as the three support systems of technology, institution and talent, and puts forward targeted optimization countermeasures. This study provides theoretical support and practical reference for promoting the high-quality development of green buildings and enhancing the competitiveness of the cross-border procurement supply chain for environmentally friendly building materials.