The problem of vehicle distribution, which often meets unknown future demand in real life, is abstracted as a problem of vehicle scheduling for internal distribution. Firstly, the competitive ratio of distribution vehicles is obtained by reset strategy analysis as 2k+f(x). Then, using the theory and method of online problem and competition strategy, the uncertain quantity relationship among distribution vehicles, distribution centers and demand points is discussed respectively, and the respective competition ratios under different circumstances are calculated. Finally, the feasibility of the model is verified by taking A company's logistics distribution data as an example, and the online scheduling problem of distribution vehicles when the demand is unknown is solved.