The invention provides a method for determining the peaking demand of a large-scale wind power integration system. The method comprises the following steps: generating a year-round wind power output time sequence; generating a year-round load time sequence; and building a conventional generator set status transfer sequence considering planned generator shutdown, determining the peaking demand of a large-scale wind power integration system, drawing a peaking demand curve, and doing statistics of peaking demand indexes. The method presented by the invention is simple, practical and highly operable. The problem that there is a need for generator set combination in the traditional method of status transfer sampling only considering forced generator shutdown is avoided. An accurate and effective analysis method and evaluation indexes are provided for solving the problem that the peaking capacity of a large-scale wind power integration system is inadequate. The peaking demand of a wind power integration system can be reflected directly. The operation stability and reliability of a large-scale wind power integration system are guaranteed.