A signal conversion circuit and a signal readout circuit are provided. The signal conversion circuit includes: an input switched capacitor, one end receiving an electric signal output by a sensing array, and the other end being coupled to an input end of an operational amplifier; a feedback switched capacitor, one end being coupled to the input end of the operational amplifier, and the other end being coupled to an output end of the operational amplifier; an input switch controlling the input switched capacitor to access the signal conversion circuit or not; and a feedback switch controlling the feedback switched capacitor to access the signal conversion circuit or not, wherein the electric signal output by the sensing array comprises a charge signal, a current signal or a voltage signal, and equivalent impedance of the input switched capacitor and the feedback switched capacitor is related to output characteristics of the sensing array.