The invention belongs to the technical field of aviation gas turbine engines, and discloses a segmented serial electric rotor turbofan engine and a control method thereof. The segmented serial electric rotor turbofan engine comprises an intermediate-pressure gas compressor, a high-pressure gas compressor, a combustion chamber, a turbine, a generator, a first speed adjusting power source, a second speed adjusting power source, a third speed adjusting power source, a controller, a power switcher, a starting power source and the like. A fan is driven by the first speed adjusting power source, the intermediate-pressure gas compressor is driven by the second speed adjusting power source, the high-pressure gas compressor is driven by the third speed adjusting power source, and therefore rotors of the fan, the intermediate-pressure gas compressor and the high-pressure gas compressor have no mechanical connection; the controller adjusts the rotating speeds of the fan, the intermediate-pressure gas compressor and the high-pressure gas compressor in real time according to the inlet and outlet airflow pressure ratios of the fan, the intermediate-pressure gas compressor and the high-pressure gas compressor; the gas compression efficiency is high; the probability that surge happens to the gas compressors can be effectively reduced; and the structure is simple.