The utility model discloses a heating steam residual pressure frequency conversion electricity generation cascade utilization system, including boiler, high pressure cylinder, intermediate pressure cylinder, low pressure jar, first valve, steam turbine, heating network heater, second valve, variable -frequency generator and hot user side, the single heat export of boiler is linked together with the entry of high pressure cylinder, the export of high pressure cylinder is linked together with the secondary heating of boiler entry, the secondary heating export of boiler is linked together with the entry of intermediate pressure cylinder, the export of intermediate pressure cylinder is linked together with the entry of low pressure jar and the entry of first valve respectively, the export of first valve divide into two the tunnel, wherein be linked together through steam turbine and heating network heater's exothermic side entrance all the way, another way is linked together through second valve and heating network heater's exothermic side entrance, heating network heater's the export and the export of low pressure jar are linked together with the single heat entry of boiler, the output shaft of steam turbine is connected with variable -frequency generator's drive shaft, this system can realize steam energy's cascade utilization.