The invention provides a rotor system and a micro gas turbine generator unit. The rotor system comprises a rotating shaft, a thrust bearing, a first radial bearing, a motor, a second radial bearing, agas compressor and a turbine, wherein the rotating shaft is of an integrally-formed structure, and the thrust bearing, the first radial bearing, the motor, the second radial bearing, the gas compressor and the turbine are sequentially arranged on the rotating shaft. The rotating shaft rotates in a stator of the thrust bearing, the first radial bearing, a motor stator and the second radial bearing, and the rotating shaft is fixedly connected with a thrust disc of the thrust bearing, a worm wheel of the turbine and a compression wheel of the gas compressor. The integral rotating shaft is adopted for connecting a micro gas turbine rotor and a generator rotor, the thrust bearing is arranged at the end with a generator, and the technical problem that the arrangement position of the thrust bearing is limited in the prior art is solved.