In recent years, e-commerce enterprises have begun to utilize digital platforms to explore agricultural supply chain business. In this paper, we consider the loss aversion behavior of farmers and compare three financing models: bank financing, platform direct financing, and platform guarantee financing. The results of the study show that the platform's choice of financing model is highly dependent on the degree of loss aversion and financial scarcity of the farmers. For the platform, when the farmers exhibit high loss aversion and low capital scarcity, platform guarantee financing is optimal; otherwise, platform direct financing is optimal. For both the farmers and the whole supply chain, platform guarantee financing is optimal. Overall, when the farmers have high loss aversion and low capital scarcity, platform guarantee financing can realize a win-win situation for both the platform and the farmers and improve the efficiency of the agricultural supply chain. The results of the study provide an explanation for the practical application of platform guarantee financing, and offer a reference for management decision-making of similar businesses in practice.