The invention belongs to the field of power system analysis, and particularly relates to a heat storage capacity configuration method considering peak regulation cost and containing a heat storage fire motor set. Aiming at the balance relationship among the heat storage capacity, the heat storage cost and the peak regulation cost, the method has the characteristics that the method is characterizedin that thermoelectric decoupling is used as the premise; the method starts from the operation characteristics of the thermal power generating unit; the influence of thermal power generating unit power generation grid connection on power grid peak regulation is analyzed; the heat storage capacity configuration method of the heat-storage-containing fire power generator set considering the peak shaving cost is provided on the basis, the balance points of the heat storage cost, the peak shaving cost and the heat storage capacity are found on the basis of economy, and therefore reasonable configuration of the heat storage capacity of the heat-storage-containing fire power generator set is achieved, and the advantages of being scientific, reasonable, accurate in capacity configuration, good ineffect and the like are achieved.