A detection system is disclosed herein, the detection system includes a first detection device. The first detection device operates at a first operating power to capture a first image data. Wherein, when the first detection device determines there are differences between a plurality of first frames in the first image data, the first detection device switches to operate at a second operating power to capture a second image data, and the first operating power is less than the second operating power. And the first detection device determines whether the second image data matches an identification data to generate a determining result, and generates a notification signal according to the determining result.