The detection circuit for recognizing a feature structure includes a sensing sub-circuit and a processing sub-circuit; the sensing sub-circuit is configured to output a first signal containing only noise information of the sensing sub-circuit to the processing sub-circuit, and the sensing sub-circuit is also configured to sense the feature structure to obtain a second signal containing information of the feature structure and output a third signal comprising a first signal and a second signal to the processing sub-circuit, and the processing sub-circuit is configured to perform differencing on the first signal and the third signal to output the second signal.