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.