Self-correcting detection circuit for extremely weak optical signal

The invention relates to a self-correcting detection circuit for an extremely weak optical signal. The self-correcting detection circuit is characterized by comprising a controlled light source, an optical fiber, a photovoltaic conversion unit, an amplification unit and a central processing unit, wherein the central processing unit is used for controlling the closing of the controlled light source after the controlled light source excites fluorescence for preset time, the central processing unit is used for receiving a signal of the amplification unit and comparing the signal with a preset value so as to judge whether the amplification unit is in an operational amplifier linear working area, if the amplification unit is not in an operational amplifier linear working area, after the central processing unit changes the working state of the amplification unit, the judgment is carried out again, and if the amplification unit is in the operational amplifier linear working area, a fluorescence signal is sampled and measured. The self-correcting detection circuit can be used for realizing the accurate measurement of the extremely weak optical signal and has the advantages of high signal to noise ratio, high accuracy, high bandwidth, low cost, stable working, and the like.