A power-saving sensing module includes a light source, a first and a second sensor, a first and a second detection unit, and a controller. The first sensor detects a touch of an external object to generate a first sensing signal corresponding to the touch. The first detection unit generates a touch signal corresponding to the first sensing signal. The second sensor senses a second sensing signal corresponding to the external object in response to the light ray. When the touch signal is greater than a touch threshold value, the second detection unit outputs a displacement signal corresponding to the second sensing signal. The controller outputs a control signal in response to the touch signal of the first detection unit and the touch threshold value, so that the second detection unit operates at a dormant state or a sensing state in response to the control signal.