The invention discloses a generalized frequency conversion system for a steam turbine generator set, which at least includes a steam turbine with adjustable speed, a feed water pump, a generator, a speed-increasing gearbox, a frequency conversion bus and auxiliary machines connected thereto; Change, correspondingly adjust (change) the steam parameters and extraction steam entering the steam turbine, so that the speed of the steam turbine changes accordingly, so that on the one hand, the speed of the feed pump is changed through the speed-increasing gearbox, and on the other hand, the frequency of the alternating current output by the generator is changed. The invention does not need additional frequency converters of other types, and the system is simple, reliable, low in cost and high in efficiency.