Blockchain technology (BCT) has changed the operating process of supply chain finance (SCF). The information transparency provided by BCT can mitigate debtors’ moral hazards and further enables the credit of the supply chain’s core enterprise to be transmitted among various supply chain tiers. Meanwhile, BCT’s smart contracts can anchor a debtor’s specific revenue source and automatically use it to repay the loan debts, thereby reducing the creditor’s credit risk. Based on these above features of BCT, this study formulates a model of confirmed warehouse financing under a blockchain-driven buy-back guarantee across supply chain tiers (CWB) and uses traditional trade credits among multiple supply chain tiers (TTC) as the benchmark. Game equilibrium analysis of these two financing modes show that: 1) The equilibrium order quantity under TTC is independent of the credit risk among supply chain tiers, whereas the equilibrium order quantity under CWB is increased by the risk-sharing effect resulting from the buy-back guarantee offered by the core manufacturer. Therefore, CWB can unconditionally increase the whole supply chain performance. 2) When the retailer’s initial working capital is at a medium level, supply chain participants can achieve Pareto improvement via CWB. 3) The BCT platform can make suitable charging and subsidizing strategies to guide supply chain participants to achieve Pareto improvement through CWB. This paper reveals that CWB can improve overall supply chain performance and achieve a Pareto improvement, which provides theoretical and practical guidance for the successful implementation of BCT in the SCF field.