The invention relates to a transmission and distribution electromagnetic spectrum joint detector, which is characterized by comprising a heat source peak spectrum receiving device, a signal adjusting circuit and a processing device, wherein a receiving end of the heat source peak spectrum receiving device is placed around electromagnetic equipment and is connected with the processing device through the signal adjusting circuit; and the processing device is connected with a display. The transmission and distribution electromagnetic spectrum joint detector has a rational structure, is convenient to use and provides technical guarantee for safe operation of power equipment. The transmission and distribution electromagnetic spectrum joint detector has the characteristics of automatic measurement, high resolution, accuracy in measurement, easiness and convenience for operation, high degree of automation and the like. Early failure in the electric equipment can be quickly and accurately judged by detecting temperature of equipment conductor, an inner core of a carbon fiber wire, an inner core of a mixed wire and an insulating material, so that a completer and more effective technical means is provided for insulation defect diagnosis of the equipment; and the transmission and distribution electromagnetic spectrum joint detector can be widely applied to industrial departments such as power, petroleum and chemical industry.