A power-saving management method for a computer peripheral device and a system thereof are described, which are applicable to stop the operation of at least one functional electronic element of the computer peripheral device, when the computer peripheral device enters a power-saving mode. The method includes the following steps. A sensor is activated to detect an environmental parameter value of the computer peripheral device. If the environmental parameter value is changed, the functional electronic element is activated to enter an operating mode, and an operation state of the functional electronic element is detected within a counting time. If the functional electronic element does not perform any operation, the sensor is reset and records the finally changed environmental parameter value, and the functional electronic element is made to enter the power-saving mode once again.