The present disclosure provides an analog readout preprocessing circuit for a CMOS image sensor and a control method thereof. The analog readout preprocessing circuit comprises an extended count-type integration cycle-successive approximation hybrid analog-to-digital conversion capacitor network 1 configured to achieve readout and analog-to-digital conversion of signals output from the CMOS image sensor; an operational amplifier configured to utilize “virtual short” of two input terminals of the operational amplifier and the charge conservation principle, to achieve a function of extended count-type integration cycle-successive approximation hybrid analog-to-digital conversion, where the extended count-type integration can effectively reduce a thermal noise and a flicker noise within the image sensor; a comparator configured to compare voltages at two terminals to achieve a function of quantization of signals; and a control signal generator configured to provide control signals.