Abstract: To address the issue of food delivery loss risk, this study proposes a cost-sharing model between a food delivery platform and couriers to improve user satisfaction and courier delivery incentives. The game theory is adopted to analyze the multi-agent interactions in the food delivery market and to clarify the risk transmission mechanism between platforms and couriers. The backward induce method is then utilized to derive the equilibrium results, including the optimal cost-sharing ratio, courier utility, platform profit, and total system utility. Results show that the platform can efficiently stimulate courier incentives, so as to improve overall service efficiency and total system utility by appropriately sharing part of cost related to delivery loss risk. Further analysis shows that the performance of the cost-sharing model is affected by factors such as the weight of courier utility, external risk level, risk sensitivity parameters, delivery time, and order attributes. In high-risk or high-uncertainty scenarios, the platform should assume a larger share of risk cost to avoid reducing courier incentives. In contrast, in medium- and low-risk scenarios, the platform can moderately transfer risk cost to couriers to establish a win-win risk-sharing mechanism.