As the platform economy evolves, well-resourced platforms can provide digital technology empowerment and loan services to farmers, thereby helping them address challenges in improving planting technology and alleviating capital shortages. This paper constructs a three-tier agricultural supply chain consisting of a platform, a company, and a capital constrained farmer, where the company can assist the farmer in obtaining financing through a guarantee mechanism. Based on bank financing and platform financing models, this study investigates the operation and financing strategies of agricultural supply chains under platform digital technology empowerment. The research findings indicate that under the bank financing model, the company is willing to provide guarantee for the farmer. Under the platform financing model, the company’s guarantee strategy is affected by the commission rate and the probability of normal agricultural harvest. The platform always prefers to offer platform financing, while the farmer’s financing choice is affected by the commission rate and the platform’s digital empowerment cost coefficient. We further expand the research on the basic model and find that when the bank occupies a monopolistic position in the market, adopting the platform financing model becomes the optimal strategy for all participants in the supply chain. Furthermore, if the farmer has a risk-averse tendency, it is disadvantageous to the company and the platform, but it may increase the farmer's own expected profit.