A power-saving sensing module includes a light source, first and second sensors, first and second detection units, and a controller. The first sensor detects a first image corresponding to a working plane in response to at least a part of the light ray from the light source to generate a first sensing signal. The first detection unit generates a displacement signal in response to the first sensing signal. The second sensor detects a second image corresponding to an object in response to at least a part of light ray to generate a second sensing signal. The second detection unit generates a touch signal corresponding to the object in response to the second sensing signal. The controller outputs a control signal in response to the touch signal. The first detection unit operates at a dormant state or a sensing state in response to the control signal.