A method for controlling a sensor includes steps of: sensing an object for determining whether the object is within a sensing range of the sensor; if it is determined that the object is not within the sensing range, the sensor is turned into a non-active mode for a predicted non-active time, wherein the predicted non-active time is calculated based on a predetermined or a historical non-active time; sensing the object for determining whether the object is within the sensing range during the predicted non-active time; and if it is determined that the object is not within the sensing range during the predicted non-active time, the sensor is turned into a sleep mode for an predicted sleep time, wherein the predicted sleep time is calculated based on the predetermined non-active time and a predetermined sleep time, or is calculated based on the historical non-active time and a historical sleep time.