A signal processing circuit for receiving a sensing signal from a sensor includes a capacitor group, an amplifier and a switch. The sensing signal consists of a common-mode part and a differential-mode part. The capacitor group, coupled to a node, includes an input capacitor for coupling the sensing signal to the node and a compensation capacitor for coupling a compensation signal to the node. The amplifier, coupled to the node, is configured to amplify the sensing signal coupled from the input capacitor. The switch is coupled between the node and the amplifier.