Abstract: In order to reveal and analyze the impact of the supply interruption, which occurs under the coupling condition between the two subjects of the supplier and contractor-based secondary supply chain, on the supplier's optimal decision-making and the contractor's cost, the supplier's high exit risk is taken as a research object. While knowing only the output mean and variance, the worst-case robust decision-making method proposed by Scarf is used and the feedback of the supply chain system under different decision-making situations is set and the game process of the secondary supply chain under different exit criteria analyzed. Based on the theoretical simulation of the robust model, the numerical simulation results show that when the exit criterion α is 100, the intermediate variable is in the range of 290~350, and the supplier has the optimal decision, but the contractor's optimal decision cannot be determined; compared with α being 0, when the order quantity reaches a certain state, that is, α when is 140, the contractor's cost increases by 1.5%, indicating that the contractor's cost is positively related to the supplier's exit criteria. The higher the exit standard, the greater the impact on the contractor's cost. This conclusion provides a new perspective for the mechanism of supply disruption in the initial stage of unstable supply chain and incomplete information.

Key words: supply interruption, partial information, robustness, optimal decision, worst-case