With the development of chip technology and refrigeration, the dark current of CCD can be neglected. At this time, the amplifier becomes the main noise source, which limits the detection of weak signals. By using the electronic multiplication (EM) technology to amplify the charge packet, the noise of the amplifier can be effectively suppressed. However, the charge packets are easily saturated after amplification, which limits the dynamic range of the device. Therefore, a floating gate amplifier and a charge packet router are made on the device, and the floating gate amplifier performs nondestructive detection on the charge packets. According to the detection results, the router outputs the large charge packets directly, while the small charge packets are amplified by electron multiplication and then output, thus obtaining high sensitivity and large dynamic range, which can reach 150000 times. A good low-light imaging effect is obtained under 10-4 Lx light.