The utility model relates to a generator protection system for hydropower has a feedback control, including wireless connection's hydropower equipment and intelligent communication terminal, this a generator protection system for hydropower has a feedback control passes through hydropower equipment and intelligent communication terminal wireless connection, has realized that the staff is to the long -range accent of hydropower equipment, after while speedtransmitter's the detection data feedback, control through the switch module to realize the feedback control principle, guaranteed to carry out the accurate control to the rotational speed of hydropower machine, improved the reliability of protection of hydropower machine, moreover, can switch the detection to the interval rotational speed of friction speed through select switch among the processing circuit, thereby improve the accuracy nature to the tachometry, through third electric capacity and the LC filter circuit that an inductor group becomes, there is filter effects to interfering signal to system signal processing's reliability and accuracy nature have been improved.