Abstract: A device for measuring surface-temperature of a turbine blade, the device including a probe having a front-end mirror for receiving infrared radiation of a surface on the blade, a collimation lens for refracted the infrared radiation, a PD detector to receive the infrared radiation, and a focal-length servo; and a radial-scanning servo connected to the probe. The front-end mirror, the collimation lens, and PD detector are disposed along the optical axis of the collimation lens. The focal-length servo is adapted to move the collimation lens along the optical axis of the collimation lens. The radial-scanning servo is adapted to move the probe along the optical axis of the collimation lens. The device of the invention is capable of accurately targeting a particular point on the blade having an irregular shape for temperature measurement to accurately detect the temperature distribution on the surface of the blade.