A synchronous rectifier control circuit, comprising: a current transformer CT, a bridge rectifier, a comparator, and a voltage source,wherein: the current transformer CT is configured to be connected in series to a secondary side of a power loop, perform sampling on a loop current of the secondary side to obtain a current detection signal, and output the obtained current detection signal to the bridge rectifier; the bridge rectifier comprises a first resistance and four diodes (D1,D2,D3,D4) and the four diodes are a first diode, a second diode, a third diode and a fourth diode, an anode of the current transformer is connected to an anode of the first diode, a cathode of the first diode is connected to a cathode of the second diode and connected to one end of the first resistance, the anode of the first diode is connected to a cathode of the third diode, an anode of the second diode is connected to a cathode of the fourth diode, an anode of the third diode, an anode of the fourth diode and the other end of the first resistance are connected to ground; a cathode of the current transformer is connected to the anode of the second diode; and the comparator is configured to receive a secondary-side sampling current that is output by the bridge rectifier, and generate a voltage difference, so that an output signal of the comparator is inverted to control on and off of a synchronous rectifier transistor, wherein the comparator is a current mirror comparator comprising a first triode, a second triode and a comparator diode, wherein an input end of the first triode is connected to an input end of the second triode, the input end of the first triode is connected to a first output end of the second triode through the comparator diode, and the input end of the first triode is connected to a first output end of the first triode. wherein a second output end of the second triode is connected to the bridge rectifier, wherein a second output end of the first triode receives the secondary-side sampling current that is output by the bridge rectifier, and wherein an emitter of the second triode generates a voltage difference, so that the output signal of the comparator is inverted. the current transformer CT is configured to be connected in series to a secondary side of a power loop, perform sampling on a loop current of the secondary side to obtain a current detection signal, and output the obtained current detection signal to the bridge rectifier; the bridge rectifier comprises a first resistance and four diodes (D1,D2,D3,D4) and the four diodes are a first diode, a second diode, a third diode and a fourth diode, an anode of the current transformer is connected to an anode of the first diode, a cathode of the first diode is connected to a cathode of the second diode and connected to one end of the first resistance, the anode of the first diode is connected to a cathode of the third diode, an anode of the second diode is connected to a cathode of the fourth diode, an anode of the third diode, an anode of the fourth diode and the other end of the first resistance are connected to ground; a cathode of the current transformer is connected to the anode of the second diode; and the comparator is configured to receive a secondary-side sampling current that is output by the bridge rectifier, and generate a voltage difference, so that an output signal of the comparator is inverted to control on and off of a synchronous rectifier transistor, wherein the comparator is a current mirror comparator comprising a first triode, a second triode and a comparator diode, wherein an input end of the first triode is connected to an input end of the second triode, the input end of the first triode is connected to a first output end of the second triode through the comparator diode, and the input end of the first triode is connected to a first output end of the first triode. wherein a second output end of the second triode is connected to the bridge rectifier, wherein a second output end of the first triode receives the secondary-side sampling current that is output by the bridge rectifier, and wherein an emitter of the second triode generates a voltage difference, so that the output signal of the comparator is inverted.