The invention discloses a peak-regulating power station integrating IGCC and a supercritical unit, and a peak regulating method. The peak-regulating power station comprises an IGCC power generator set and a supercritical power generator set, wherein a gasifier outlet in the IGCC power generator set is connected with a purification unit synthesized gas inlet, a purification unit outlet is divided into two ways, one way is connected with a combustion chamber of a gas turbine to implement the quick variable load of the peak-regulating power station by regulating the synthesized gas inlet volume of the gas turbine, and the other way is connected with a synthesized gas burner of the supercritical boiler in the supercritical power generator set; an extraction pipeline in steam cylinder of the supercritical steam turbine which is provided with steam by the supercritical boiler is connected with a steam regulator, an outlet of the steam regulator is connected with a combined cyclic steam turbine inlet pipeline in the IGCC power generator set; the two ways are organically fused through the connection and coordinated matching of pipelines among the systems, the quick and deep peak regulating capability of the power station can be realized, and the relatively high power generation efficiency can be kept.