A signal conversion circuit and a signal readout circuit are provided. The signal conversion circuit includes: an operational amplifier, configured to amplify an electric signal output by a sensing array; an input switched capacitor, wherein an end of the input switched capacitor is configured to receive the electric signal output by the sensing array, and another end of the input switched capacitor is coupled with an input end of the operational amplifier; and a feedback switched capacitor, wherein an end of the feedback switched capacitor is coupled with the input end of the operational amplifier, and another end of the feedback switched capacitor is coupled with an output end of the operational amplifier.