The invention provides a method for analyzing a machine set spinning reserve cost in a wind power system. The method comprises the following steps: I, determining a total reserve cost of the wind power system; II, determining a machine set bearing wind power intermittent fluctuation reserve in a conventional machine set; and III, determining the machine set spinning reserve cost of the wind power system according to a spare space proportion sharing method. The invention provides a wind power reserve cost sharing method, and provides the wind power intermittent fluctuation reserve cost of each machine seat at each time period, the method is simple in principle, and the provided cost value can lay a foundation for the research on the transaction mechanism of the conventional machine set and the wind power machine set.