The utility model discloses a surface acoustic wave (SAW) temperature sensor for outdoor high-voltage environment. The SAW temperature sensor includes a fixed device fixed onto a tested object, and a SAW temperature detection device which is mounted on the fixed device and is used for detecting the temperature of the tested object. The SAW temperature detection device includes a heat-conducting ceramic circuit board, and a temperature sensor chip and a helical antenna which are welded to the upper plane of the heat-conducting ceramic circuit board. The bottom surface of the heat-conducting ceramic circuit board fits and is fixed to the fixed device. The temperature sensor chip and the helical antenna are enclosed by a sealing cap in a sealed manner. The SAW temperature sensor is small in size and light in weight, does not need an external power source and works in a wireless mode, has a waterproof characteristic and an insulation property, and is suitable for temperature measurement in an outdoor high-voltage environment.