A test device and method for testing a distributed feedback laser diode (DFB-LD) device for an optical transceiver of a radio over fiber (RoF) system examines the DFB-LD device based on an absolute limiting rating, an operating case environment, and a functional specification, in which the absolute limiting rating is a rating at which there is no fatal damage to the DFB-LD device during a short period of time when each limiting parameter is isolated and all other parameters are in a normal performance parameter, the operating case environment includes an operating temperature, and the functional specification includes parameters to be tested according to an operating condition for the functional specification.