The utility model relates to a photoelectric converting circuit of thyristor breakdown detection which is used in the high voltage static type dynamics reactive power compensating device. The utility model is used for changing the light signal into the electrical signal to output after transferring the light signal by the optical fiber; the main operational principle of the circuit is that after the photoelectric receiving head changes the light signal into the electrical signal, utilizing the switching characteristic of the transistor, the electrical signal is output. The circuit is used for changing the light signal and the electricity between the photoelectric converting circuit of thyristor breakdown detection and the control system.