The invention discloses a device for monitoring temperature of a generator breaker. The device comprises an infrared viewing window and an infrared thermometer, wherein the infrared viewing window is arranged on a shell of an enclosed bus at the generator breaker, the infrared thermometer is arranged outside the enclosed bus, and the infrared thermometer is used for monitoring the temperature of the generator breaker through the infrared viewing window. The device provided by the invention has the following advantages that: (1) the structure of the viewing window is simple, and the implementation is convenient; and (2), the infrared thermometer is adopted to monitor temperature rise accurately and conveniently.