From the perspective of financial services, management services and coordination services, this paper analyzes the internal mechanism of agricultural supply chain finance (ASCF) to help sustainable poverty reduction (SPR). The internal and external driving forces of ASCF for SPR are also explored. Among them, the internal driving forces include industrial upgrading and financial transformation; External driving forces include technological change, policy guidance and market drive. Based on the background of digital technology, the green agricultural supply chain finance (GASCF) model has been innovatively proposed. We mainly analyze the core elements and platform structure of GASCF, and focus on the process design and key points of the three modules of the GASCF platform: risk control port, credit port and capital port. Finally, we analyze the practical difficulties of green agricultural supply chain finance in helping sustainable poverty reduction, such as the lack of comprehensive management ability of the organization, the insufficient application of digital technology, the imperfect institutional environment and the lack of compound talents. And we put forward accordingly a four in one path of GASCF helping SPR, which is "Government standardizing and leading, assistance from financial institutions, driven by industry subjects and Co governance of Social Service ".