The invention discloses a transformer substation bus joint temperature sensor comprising a temperature displayer, an indicating lamp, an alerter, an infrared probe, a power supply and buttons. Temperature of a bus joint is acquired by the temperature sensor, and temperature display is real-time and accurate and has relatively high anti-interference capability so that temperature of the joint can be reliably displayed in strong electromagnetic, high-noise, high mechanical vibration and other complex environments of a transformer substation in real time; and temperature signals are acquired by adopting the temperature sensor, AD analog-to-digital conversion is performed, temperature is displayed by the displayer and functions of data standard exceeding alarm can be realized. Besides, the transformer substation bus joint temperature sensor is small and convenient, the signals are transmitted by a data line, remote monitoring can be realized, and the main components include the temperature sensor, a data transmission channel and a far-end display and alarm device so that temperature real-time monitoring and temperature standard exceeding alarm can be realized.