A control device of a temperature controller, for adjusting the temperature of an environment having at least one active object, includes a first image sensor, a second image sensor, a process unit and a control unit. The first image sensor is for capturing a first image containing the image of the active object. The second image sensor is for capturing a second image containing the image of the active object. The process unit calculates a distance between the active object and the temperature controller according to the first and second images. The control unit controls an operational status of the temperature controller according to the distance calculated by the process unit. The present invention further provides a control method of a temperature controller