The invention discloses a comprehensive offline test platform of a generator rotor insulation measurement device. The comprehensive offline test platform of the generator rotor insulation measurement device comprises a rotary experimental platform and control console connected with the rotary experimental platform, wherein the rotary experimental platform comprises a motor, a sliding ring shaft, a sliding ring and a first carbon brush which are installed on the rotary experimental platform. The sliding ring shaft is connected to a driving shaft of the motor, and the sliding ring sleeves the sliding ring shaft and rotates with the sliding ring shaft. During testing, the motor can reach to a rated rotation speed, and the first carbon brush is lifted to be in contact with the sliding ring and output an electric signal. The control console comprises a motor power distribution and control loop, a carbon brush power distribution and control loop and an oscilloscope. During testing, the oscilloscope is used for recording waves, and the situation that waveforms of input electrical signals are free of clutters is confirmed. Accordingly, when the motor reaches to the rated rotation speed, the first carbon brush and the sliding ring are always in contact, and the first carbon brush does not bounce on the surface of the sliding ring. A test proves that the first carbon brush cannot bounce on the surface of the sliding ring, and accordingly the problem of ground protection false alarming of a generator rotor can be solved.