The energy-saving control system of rotating equipment can automatically calculate and process all kinds of data (signals) of the motor in real time within the deviation range of 20% of the rated voltage, intelligently diagnose the current running state of the motor, automatically optimize the power quality, realize automatic monitoring, automatic tracking and automatic regulation in turn, provide the motor with the best power quality and rectify the whole wave output, so as to keep the motor in an efficient and economical running state all the time. The control system can save electricity by more than 15-30% by transforming the power frequency equipment. The transformation of frequency conversion equipment can ensure more than 7%-12%.