Silicon-based modulator bias-point control device

The invention provides a silicon-based modulator bias point control device which comprises a first phase controller, a second phase controller, a first coupler, a second coupler, a third coupler, a photoelectric detector, a collecting module and a processing module. The first phase controller controls temperature applied to a first micro ring structure according to access voltage; the second phase controller controls temperature applied to a second micro ring structure according to the access voltage; the first coupler, the second coupler and the third coupler couple and output received light to the photoelectric detector; the photoelectric detector is used for detecting the light average power of the received light; the collecting module is used for collecting the light average power detected by the photoelectric detector and outputting the light average power to the processing module. The processing module is used for recording the light average power, comparing the light average power recorded last time with the light average power recorded this time and controlling the voltage having access to the first phase controller or the second phase controller according to the comparison result. According to the silicon-based modulator bias point control device, the area of a silicon-based chip can be saved, balance detection can be achieved, and the structure is simple.