The invention provides a surface temperature real-time measurement device in the optical film damage process. The measurement device includes a laser system, a sample to be tested on a mobile platform controlled by a computer, a CCD online damage determination device, and two Si avalanche photodiode detectors and one oscilloscope for measuring thermoreflectance signals. By means of two different lasers, one is a nanosecond pulse main laser irradiating the optical film to induce the damage of the optical film, the other one is a detection laser irradiating the sample surface at a certain angle with the main laser, and the thermoreflectance signals of the detection laser on the surface of the optical film in real time are detected to measure the real-time change of the temperature in the damage process of the optical film induced by the main laser. The system can measure the surface temperature in the nanosecond pulse laser induced optical film damage process and provides an experimental basis for the determination of the nanosecond pulse laser induced optical film damage mechanism.