an image signal processing circuit for cmos image sensor comprises a differential operational amplifier , input stage capacitors , and output stage capacitors . the input stage capacitors comprise a first positive input stage switching capacitor array and a first negative input stage switching capacitor array . the first positive input stage switching capacitor array is configured to input analog image signals , a control end of the first positive input stage switching capacitor array is connected to a color gain control signal end , and an output end of the first positive input stage switching capacitor array is coupled to a positive input end of the differential operational amplifier . the first negative input stage switching capacitor array is configured to input a reference level signal , a control end of the first negative input stage switching capacitor array is connected to the color gain control signal end , and an output end of the first negative input stage switching capacitor array is coupled to a negative input end of the differential operational amplifier . the output stage capacitors are connected between the output end and the input end of the differential operational amplifier . in the present invention , two or more control functions are implemented with a single circuit , therefore , with the imaging effects guaranteed , the circuit structure is simplified , the size of the cmos image sensor chip is reduced , and thus the cost is reduced . the present invention meets the developing trend of product miniaturization .