Abstract: A power consumption control device applied to an electronic device includes an image signal processor (ISP), a storage device, a processing circuit, and a control circuit. The ISP is arranged to receive an image signal captured by a camera of the electronic device, and process the image signal to generate a processed image signal. The storage device is arranged to store at least one predetermined image class. The processing circuit is arranged to analyze the processed image signal to detect whether the processed image signal belongs to the at least one predetermined image class to generate a control signal. The control circuit is arranged to switch a mode of the electronic device to a first mode or a second mode according to the control signal, wherein power consumption and performance of the electronic device in the first mode are lower than that in the second mode.