Abstract: Small and medium-sized enterprises often face the risk of uncertain yields. This paper assumes a supply chain financing platform built by the bank under blockchain technology and a quantitative model is applied to characterize the predictive effect of the blockchain on output uncertainty. Then, the model analyzes the impact of the application degree of blockchain technology on the planned production of the supplier, the lending decision of the bank and the expected profit of both. The bank’s loan quota decision is calculated under a downside risk model. The results show that the planned production increases with the application of the blockchain. When the bank only seeks profit maximization, the amount of loans to supplier increases under certain conditions as the application of block chain technology increases. The change of the bank’s decision on credit limit is related to the average value of uncertain yields’ fluctuation and risk tolerance. The expected profit of the supplier decreases first and then increases with the increase of the application of blockchain technology. When the average value of the supplier’s output fluctuation is large, the expected profit of the bank increases with the increase of the application of blockchain technology.

Key words: blockchain, supply chain financing, uncertain yields, credit limit